Cystic hygroma is an aberrant proliferation of lymphatic vessels resulting from abnormal development of the lymphatic system.Cervical lymphangioma is an uncommon entity, usually reported in children, rarely in adult.Our case presents a 65-year-old man with an extremely huge right-sided painless cervical swelling since 8 years with no symptoms.Computer tomography (CT) showed a cystic lesion with thin walls of 150 × 100mm, medial to right sternocleidomastoid muscle (SCM).The lesion was completely resected along with the entire capsule.Post-operatively, the patient recovered well with no signs of any neurological dysfunction and he was discharged from hospital after 2 days.The etiology in the adult population is controversial.Diagnosis in adults is considered to present a greater challenge than in children, and final diagnosis is usually based on postoperative histology.Cystic hygroma should be considered as a differential diagnosis of cervical masses in adults. WithiCystic hygroma also known as water-tumor or lymphangioma is a benign malformation of lymphatic vessels which usually occurs when the lymphatic system fails to communicate with the normal jugular vein. It can occur in the head, neck, axilla, cervico-facial regions, groin, and below the tongue .Lymphangioma is generally known as a disease of childhood when there is active lymphatic growth. Cystic Hygromas are single or multiple cysts found mostly in the neck region. A cystic hygroma can be present as a birth defect  or develop at any time during a person's life .Presentation in adulthood is rare, and the cause is uncertain, although trauma and upper respiratory tract infection have both been suggested as possible triggers for the onset .Diagnosis in adults is considered to present a greater challenge than in children, and final diagnosis is usually based on postoperative histology.In this case there was no identifiable cause and onset was sudden.We want to underline the rarity of Cystic hygroma in adults and its role in the differential diagnoses for Cervical masses in adults.Our work is a single case report and has been reported in line with the SCARE criteria ,11.2A 65-year-old Man presented to our department via community referral, complained of right-sided painless cervical swelling.Tumor onset was referred to be 8 years before it accelerated growth during recent months. There was no history of fever, trauma, toothache or pus discharge.On examination, There was a soft painless cervical lesion of about 16 × 9 cm palpable in regions II–III-IV-V on the right side. This was classified as a stage III lesion according to the staging system proposed by de Serres.The mass was painless and the patient was asymptomatic apart from some restriction of neck movement.The patient's review of systems and additional medical history surgical, family, psychosocial and pharmacologic were unremarkable.A contrast study of the neck using computed tomography (CT) showed a cystic lesion with thin walls of 150 × 100mm, medial to right sternocleidomastoid muscle (SCM), which compressed the Carotid Sheath and was displacing the trachea and oesophagus to the left, occupied the right II–III-IV-V levels and was clearly delimited by vascular and muscular structures.Fig. 1CoAfter obtaining the patient's informed consent, surgery was planned.The procedure was done by an otolaryngologist-head and neck surgeon.The neck was explored using a reverse ‘J’ shaped incision. After retracting the SCM (sternocleidomastoid muscle) for attaining wide exposure the cyst was found abutting the IJV and carotid artery which were carefully dissected away. All the important nerves and arteries encountered during the dissection were seen and preserved. The lesion was completely resected along with the entire capsule. The measurements of the Cyst were 15 × 10 × 8 cm in size.Fig. 3GrHistological examination revealed unilocular cavity filled with uncolored fluid and lined with flat endothelial-like cells consistent with a diagnosis of cystic hygroma.Post-operatively, the patient recovered well with no signs of any neurological dysfunction and he was discharged from hospital after 2 days.Routine follow-up by clinical observation and ultrasound was done for past 11 months. There was no recurrence until now.3Cystic Hygromas, also called lymphatic malformation, are anomalies of the lymphatic system characterized by single or multiple cysts within the soft tissue .Lymphangioma, soft tissue tumor of disputed pathogenesis was originally reported by Reden Backer in 1828 and “cystic hygroma” name was first given by Wernker in 1834 [Hygromas are probably the result of sequestration of lymphatic tissue that has retained its potential for growth in any of these areas .The etiology in the adult population is controversial. Some authors attribute adult lymphangioma to delayed proliferation of the congenital or acquired lymphoid rests following trauma or preceding respiratory infections .There are three histological subtype of lymphangioma's. Capillary lymphangioma , cavernous lymphangioma (composed of larger lymphatics), cystic lymphangioma (cystic hygroma-composed of large macroscopic lymphatic spaces with collagen and smooth muscle). Cavernous lymphangioma is the most common subtype .The present case was unusual, as a large cervical cystic hygroma presented de novo in an adult with no history of trauma or upper respiratory tract infection.They are locally aggressive, benign lesions that are difficult to manage due to recurrence of the tumor following surgery with a recurrence rate of 21% .Many treatment alternatives exist for lymphangiomas, including surgical excision, laser surgery, cryotherapy, electrocautery, steroid administration, sclerotherapy, embolization and radiation therapy, but surgical excision is the most preferred option.4Cystic lesions of the neck are rare and difficult to interpret for clinicians, since they can be benign or malignant pathologies.Cystic hygroma although known in pediatric age group can present at any age and should be considered as a differential diagnosis of cervical masses in adults. Surgery is the best modality of treatment and the first operative intervention offers the best opportunity for complete excision.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.This study was not applicable for ethical approval.I have obtained written consent for publication of this case report from the patient and I can provide this should the Editor ask to see it.Dr. Ali Hammed (corresponding author): Contribution to the paper: data collection, data analysis and interpretation, writing the paper.Prof Dr. Areeg Alassaf: Contribution to the paper:Main Surgeon. Treatment and examination of the patient.Writing Case Presentation.Dr. Salah Hammed: Contribution to the paper: First author, Writing the paper.Dr. Ziad Saker: Contribution to the paper: Writing the paper.Dr.Ali dway: Contribution to the paper: Writing the paper.The case report at hand is not a first-in-man case report of a novel technology or surgical technique, therefore a registration of these case reports according to Declaration of Helsinki 2013 is not required.Dr. Ali Hammed.Not commissioned, externally peer-reviewed.All authors declared no conflict of interest.


Isolated diaphragmatic metastasis is rarely associated with periosteal osteosarcoma.A 24-year-old female patient was found to have periosteal osteosarcoma of the right humerus 11 years ago. Computed tomography showed a mass in her left chest in 2018, and thoracotomy was performed to remove the tumour. The tumour showed the same characteristics as the original periosteal osteosarcoma. Genetic analysis of the tumour sample showed a TP53 point mutation and CCNE1 gene copy number variants.We believe this is the first case report of haematogenous metastasis to the diaphragm of periosteal osteosarcoma, and an investigation of the genetic factors may help to unravel the underlying cause of periosteal osteosarcoma. Periosteal osteosarcoma (PO) is an uncommon primary malignant bone tumour that represents less than 2% of all osteosarcomas. Compared with conventional osteosarcoma, periosteal osteosarcoma presents less aggressive biological behaviour and a lower tendency to metastasize. We herein report an unusual case of isolated diaphragmatic metastasis that originated from periosteal osteosarcoma 11 years later.In 2008, a 24-year-old non-smoking female was admitted to the hospital for right upper limb pain. On examination, she appeared to have a tender fusiform bony-hard swelling of the right upper arm. An X-ray scan showed an extraosseous tumour on the periosteal surface mainly in the mid humerus. A biopsy of the lesion was performed, with the histological result confirming periosteal osteosarcoma diagnosis. Computed tomography (CT) of her thorax and emission computed tomography (ECT) scan demonstrated no metastases. Segmental resection of the proximal periosteal osteosarcoma with internal fixation grafting was performed. The histology report demonstrated the presence of periosteal osteosarcoma. The report indicated that the local excision was complete with wide excision margins. She received adjuvant therapy postoperatively with 4 cycles of a cisplatin and doxorubicin regimen.We followed the patient every 6 months with routine complete blood counts and liver function, serum alkaline phosphatase, and lactate dehydrogenase level tests, along with X-rays of the right humerus. ECT and CT scans of the chest were performed annually. No signs of recurrence were found through these examinations. However, chest CT found a mass in her left chest for the first time in December 2018. The mass was 5.5 cm, and the mass increased to 6.1 cm half a year later  mutation in two PO patients . TP53 isThere has been very little research or case reports describing the details of recurrence. We believe this is the first case report of haematogenous metastasis to the diaphragm of periosteal osteosarcoma. Wide surgical removal of the tumour is the best treatment to cure the disease. Chemotherapy treatment plays a controversial role in improving the survival rate for these patients. Genetic factors must be examined to unravel the underlying cause of PO during initial phases of diagnosis and care.


Transdiaphragmatic intercostal herniation can occur following blunt or penetrating trauma and is usually associated with rib fractures. It is uncommon and only sporadically reported in literature. We report a case of cough-induced intercostal herniation containing large bowel, on a background of sustaining a blunt chest trauma 25 years prior to presentation. The patient was treated by reducing the hernia followed by surgical repair of the diaphragm and intercostal muscles defect. He was discharged without further complications and remained well at follow-up. If it is missed during the post-traumatic period, the patient may recover from the initial trauma and remain symptom free, present with chronic thoracoabdominal symptoms or present as an acute emergency with a symptomatic hernia.2 During a delayed presentation, the initial trauma responsible for the injury is often forgotten and the diagnosis may not be suspected.3 A careful history, physical examination and appropriate imaging are required for the prerequisites of an accurate diagnosis.Transdiaphragmatic intercostal herniations (TDIH) is a rare clinical entity characterised by the protrusion of abdominal viscera through the diaphragm and a defect in an intercostal space. They generally develop after trauma, surgery or rarely spontaneously.This case is unique due to the occurrence of TDIH as a delayed presentation, with a subtle factor precipitating the symptoms.A 58-year-old male presented to the emergency department with a 10-day history of poorly localised pain on the left side of his chest and upper abdomen, exacerbated by movement. The symptoms preceded a paroxysmal of cough, which precipitated a sudden bulge and ecchymosis over left inferolateral region of the chest. Additionally, he complained of absence of bowel motions for four days and nausea. He had a history of blunt trauma to the chest and abdomen following a high-speed motor bike accident 25 years ago, whereby he suffered rib injuries to his left side. He did not seek medical attention at the time.th and 11th intercostal space, which became increasingly evident during a Valsalva manoeuvre. Abdominal examination revealed tenderness in the left upper quadrant with decreased bowel sounds on auscultation. Apart from raised inflammatory marker (CRP 159 mg dl−1), all the blood tests were within normal limits. A chest radiograph showed an abnormal lucency in the left lower zone with an appearance of a bowel loop. The lucency was seen extending into the soft tissue of the lateral chest wall concerning for a diaphragmatic and lateral chest wall hernia. The remaining lung fields were clear , and constriction of the bowel and the herniated organs at the site of the diaphragmatic defect (collar sign).4Investigations for diagnosis should be commenced with a chest radiograph. Although it presents low sensitivity and specificity, its preoperative diagnostic value is further limited in the presence of right-sided diaphragmatic defect or haemothorax.5 The complications associated with undiagnosed diaphragmatic rupture may include; bowel herniation, incarceration and strangulation; tension haemothorax secondary to massive bowel herniation; pericardial tamponade from herniation into the pericardial sac.2The morbidity and mortality rate can increase secondary to associated complication of the undiagnosed diaphragmatic injury, mortality ranges from 5–30%.7 Analysis of the costal margin, diaphragm and intercostal muscles can be used to categorise the injuries.7 Surgery should address each of the components of injury to maintain a sound repair. In the setting of an acute rupture, resuscitation followed by an operative intervention is mandatory to prevent bowel ischaemia and rupture. A thoracoabdominal incision is preferred in cases of delayed presentation to look for concomitant abdominal injury and for ease of reduction and freeing of adhesions within the chest cavity.4 As in our case, repair of the hernia was easily achieved with this incision.Classification of injuries involving the costal margin is poorly described in literature and surgical management varies.Delayed presentation of TDIH should be considered in acute sitting of upper abdomen and/or lower chest pain or a sign of bowel obstruction in patients with past history of blunt or penetrating trauma involving either the lower chest or upper abdomen. CT and chest X-ray play an essential role in the diagnosis, and laparotomy with thoracoabdominal incision is advocated as operative choice for acute or delayed presentation.The diagnosis of transdiaphragmatic intercostal herniation (TDIH) is difficult and often missed particularly in delayed presentations following the trauma. This leads to an increased risk of considerable morbidity or mortality from the complication of the hernia.Chest X-ray initially will be helpful although with its limitations. CT scan has become the standard in diagnosis in recognising the signs of direct rupture and indirect signs that are associated with the consequence of the rupture.Accurate diagnosis depends on the combination of clinical and radiological findings.


Mesenteric cysts are intra-abdominal masses of congenital origin, which most frequently occur in children, with an incidence of approximately 1 case per 20,000 pediatric admissions. Its progression can be asymptomatic, and its diagnosis can be incidental. However, it usually occurs with symptoms such as nausea, vomiting, constipation, sensation of a mass, and/or diarrhea. The diagnostic imaging method of choice is abdominal ultrasound.Below, we present the case of a previously healthy 1-year-old male patient with nonspecific symptoms, who was referred to a tertiary hospital. The presence of a mesenteric cyst was detected at the end of the diagnostic approach.It is important to know these pathologies even though they are infrequent, because although they are benign masses by definition, they can lead to complications such as intestinal torsion, intestinal obstruction, and even peritonitis. Mesenteric cysts are intra-abdominal masses which very rarely occur in children (the incidence is lower in children than in adults) , 2. The The location of these cysts is more frequent in the mesentery of the small intestine, followed by the mesentery of the colon and the retroperitoneum . Most ofThe differential diagnoses of this entity include intestinal duplication cysts, diverticulitis, appendicitis, and intestinal obstruction and ovarian, choledochal, pancreatic, splenic or renal cysts. Torsion, rupture, or intestinal obstruction is among the complications that may occur –10.Described below is the case of a previously healthy 1-year-old male patient who was referred with a diagnosis of acute diarrheal disease and in whom a mesenteric cyst in the greater and lesser omenta was identified.The patient is a previously healthy 1-year-old male patient who was referred to the institution because he had the following clinical symptoms for the past 15 days: multiple diarrheic stools with mucus and without blood (6–7 per day), associated with fever spikes, the highest being 39.8 °C; abdominal distension; and irritability. No additional symptomatology. Physical examination upon admission showed a patient in poor general condition, with marked abdominal distension and a palpable abdominal mass , mild hyponatremia (Na: 134 mmol/L), potassium, chloride, and calcium within a normal range; normal glycemia; kidney function within normal parameters; and coproscopic exam does not show parasitic structures. Abdominal ultrasound shows a multiseptate image which occupies the right half of the abdomen and displaces the bowel loops and could correspond to septate ascitic fluid; distension of intestinal loops. X-ray of the abdomen where displacement of the bowel loops to the left and opacification of the right half of the abdomen is seen Fig. .Fig. 2BFollow-up tests were requested, since the patient presented signs of peritoneal irritation, which found leukocytosis, neutrophilia, and thrombocytosis, PCR (C-reactive protein) indicative of bacterial infection; previously requested blood cultures were negative. An exploratory laparotomy was carried out on suspicion of sepsis of abdominal origin which found a cystic lesion dependent on the greater and lesser omenta, attached to the greater curvature of the stomach and transverse colon, with greenish-yellow content and whitish particles inside, measuring approximately 30 cm in diameter and weighing approximately 1 kg  requires resection of the affected loops and anastomosis; type 3, which can extend to the retroperitoneum and cannot be completely resected; and type 4, which is multicentric and requires several surgeries and sometimes sclerotherapy , 12–15.These lesions can be asymptomatic and this is the reason for the incidental findings. In the case of our patient, the initial diagnostic approach of the remission site was an acute diarrheal disease, due to the multiple diarrheal episodes presented by the patient, and the associated fever; however, a large abdominal mass was palpated during the physical examination, and diagnostic images were requested.Ultrasonography of the abdomen is the diagnostic imaging of choice, and it is possible to observe a delimited mass with thin walls and cystic appearance. The findings on an x-ray of the abdomen consist of a homogeneous mass with a density similar to that of the water that displaces the intestinal loops. Magnetic resonance and computed tomography do not provide any information in addition to that which was mentioned for the other diagnostic imaging techniques , 11.In the case of our patient, abdominal radiography and abdominal ultrasound were performed when an abdominal mass was identified upon palpation, which showed displacement of the intestinal loops to the left and opacification of the right hemiabdomen, and a multiseptate image that occupied the right hemiabdomen and displaced the bowel loops, respectively.These types of masses must be handled surgically and the resectability of the mass depends on its type. Emergency surgical management was considered in our patient’s case, since the patient had abdominal distension associated with symptoms of systemic inflammatory response from the time of admission, and for this reason, sepsis of abdominal origin was considered.It is important to know these pathologies even though they are infrequent, because although they are benign masses by definition, they can lead to complications such as intestinal torsion, intestinal obstruction, and even peritonitis.


Insulinomas are rare, with an annual incidence of 1–4 people per mission. Insulinomas are the most common functioning endocrine neoplams of the pancreas. Endoscopic ultrasound has both diagnostic and therapeutic yield in undifferentiated pancreatic tumors. We present a case of a recurrent insulinoma, refractory to surgical and medical management diagnosed with endoscopic ultrasound. Our case uniquely conveys a successful, alternative approach to addressing symptomatic insulinomas refractory to surgical or medical management through computed tomography–guided percutaneous ethanol-lipiodol injection. Insulinomas are a rare neuroendocrine tumor of the pancreas. We present a unique case of a recurrent insulinoma refractory to surgical and medical management successfully treated with computed tomography (CT)-guided percutaneous ethanol-lipiodol injection.An 81-year-old woman presented to our tertiary care center with persistent episodes of hypoglycemia during which she reports palpitations, diaphoresis, and confusion. The patient's medical history was significant for recurrent hypoglycemia initially because of a 2.5-cm insulinoma at the pancreatic head diagnosed 15 years earlier at an outside hospital amendable to enucleation therapy. Symptom recurrence 7 years after the initial diagnosis was significant for a 2-cm highly differentiated neuroendocrine tumor located at the previous surgical bed treated with a pyloric-preserving pancreatoduodenectomy (Whipple procedure). She was symptom-free for another 7 years before symptom reoccurrence for the third time. Repeat endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) was nondiagnostic (no pancreatic body/tail mass or cyst), and FNA of a peripancreatic lymph node was negative for neoplastic immunohistochemistry , prompting referral to our pancreas clinic. With concern of reoccurrence of insulinoma, workup was significant for C-peptide 4.5 ng/mL, proinsulin 302 pmol/L, and abdominal magnetic resonance imaging (MRI) found a 3.8-cm heterogeneous mass posterior and caudal to the pancreatic anastomosis from previous Whipple procedure  was not considered because of the size of the mass and preference of chemical ablation. Surgical debulking was not an option because of the tumor's retroperitoneal location and patient's altered postsurgical anatomy. Interventional radiology conveyed that CT-guided percutaneous ethanol-lipiodol injection of the insulinoma was an option that has been used to treat other types of tumors in the past. It was decided to proceed with CT-guided percutaneous ethanol-lipiodol injection Figure D. The pa3 Our patient's tumor was recurrent and >2 cm on multiple admissions despite enucleation, Whipple procedure, and medical management with diazoxide.The majority of insulinomas follow the “90% Rule” in which the majority are benign (90%), solitary (90%), < 2 cm (90%) in diameter, and equally distributed within the head, body, and tail of the pancreas.3 EUS-FNA has better sensitivity (86.8%) and specificity (95.8%) compared with conventional MRI or CT with regards to diagnosing pancreatic tumors.4 After localization of an insulinoma, surgical management is considered first-line therapy. Candidacy for surgery is mediated on size, location, and type. Enucleation of smaller masses or partial pancreatectomy of masses located within the body or tail of the pancreas is ideal to preserve pancreatic parenchyma and exocrine/endocrine function.2 Our patient, before referral to our center, had trialed enucleation and pyloric-preserving pancreatoduodenectomy with subsequent recurrence. Recurrence of insulinomas is reported to be between 5% and 20% with a higher rate of recurrence in patients with multiple endocrine neoplasia 1.5 Our patient had recurrence at 7 and 15 years after initial diagnosis, and she did not have clinical features concerning for a concurrent pituitary adenoma or hyperparathyroidism suspicious of multiple endocrine neoplasia 1.Detection methods for undifferentiated pancreatic masses are broad. Initial laboratory workup including serum insulin, c-peptide, and glucose challenge testing often leads to noninvasive imaging such as CT or MRI. However, endoscopy, in particular EUS, plays a significant role in diagnosis.6 Our patient was initially placed on diazoxide with symptoms refractory despite medical and surgical management. Because of the retroperitoneal location of the insulinoma and altered surgical anatomy from her previous Whipple procedure, it was deemed that she would not make an ideal surgical candidate because of perioperative risks.In patients who are not surgical candidates or in patients who require a bridge before invasive treatment, medical management in the form of diazoxide, a beta-cell receptor antagonist or somatostatin analogs such as octreotide and lanreotide can be used.12 Alternative approaches, especially EUS-guided approaches, should be kept in mind by gastroenterologists and advanced endoscopists alike. EUS-guided approaches are relatively new compared with CT-guided ablation, which has been practiced for over 30 years for insulinomas, hepatic neoplasms, and medullary thyroid carcinoma.14 EUS-guided ethanol-lipiodol injection would have been an equally viable option given the successful procurement of tumor tissue through EUS; however, CT-guided ablation was used in our case based on patient preference and clinical experience of the interventional radiology team with regards to CT-guided chemical ablation.Successful techniques other than surgery have been described in previous literature, including EUS-guided and CT-guided alcohol ablation, RFA, and embolization of an insulinoma.In the setting of a recurrent, retroperitoneal pancreatic insulinoma complete elimination of the tumor burden was ancillary to symptom management, and control of her symptomatic hypoglycemia was the main objective. Our patient had successful treatment through CT-guided ethanol-lipiodol injection of her insulinoma with complete resolution of her symptomatic episodes. In conclusion, EUS- and CT-guided alcohol or RFA embolization offers a less invasive alternative to surgical intervention and should be considered in patients with refractory or poorly localized pancreatic tumors. Our case uniquely conveys a successful, alternative approach to addressing symptomatic insulinomas refractory to surgical or medical management through CT-guided percutaneous ethanol-lipiodol injection.Author contributions: All authors contributed equally to this manuscript. HB Zaver is the article guarantor.Financial disclosure: None to report.Informed consent was obtained for this case report.


An asymptomatic SCUBA (Self-contained underwater breathing apparatus) diver was discovered to have an intralobar bronchopulmonary sequestration during routine pre-course screening. This is the first reported case of a diver who, having previously completed several recreational and military diving courses, was subsequently diagnosed with a congenital lung condition, possibly contraindicating diving. Presently, there is no available literature providing guidance on the diving fitness of patients with such a condition.An asymptomatic 26-year-old male diver was nominated to attend an overseas naval diving course. Prior to this, he had been medically certified to participate in, and had successfully completed other military and recreational diving courses. He had also completed several hyperbaric dives up to a depth of 50 m and 45 recreational dives up to a depth of 30 m. He did not have a history of diving-related injuries or complications. He had never smoked and did not have any medical or congenital conditions, specifically recurrent respiratory infections. As part of pre-course screening requirements, a lateral Chest X-ray was performed, which revealed a left lower lobe pulmonary nodule. This was subsequently diagnosed as a cavitatory left lower lobe intralobar bronchopulmonary sequestration on Computed Tomography Thorax. The diver remains asymptomatic and well at the time of writing and has been accepted to participate in another overseas course involving only dry diving in a hyperbaric chamber, with no prerequisites for him to undergo surgery.Although bronchopulmonary sequestrations lack communication with the tracheobronchial tree, they may still contain pockets of air, even if not radiologically visible. This can be attributed to anomalous connections which link them to other bronchi, lung parenchyma and/or pores of Kohn. As such, there is a higher theoretical risk of pulmonary barotrauma during diving, leading to pneumothorax, pneumomediastinum, or cerebral arterial gas embolism. Taking these into consideration, the current clinical consensus is that bronchopulmonary sequestrations and all other air-containing lung parenchymal lesions should be regarded as contraindications to diving. Patients who have undergone definitive and uncomplicated surgical resection may be considered fit to dive. As recreational SCUBA (Self-contained underwater breathing apparatus) diving continues to gain popularity , physiciBronchopulmonary sequestrations (BPS) constitute 0.15–6.4% of all congenital pulmonary malformations . They coThere is presently no literature or guidelines governing the fitness to dive for individuals with BPS. This is the first reported case of a SCUBA diver having previously cleared pre-diving medical screening, and completed several military and recreational diving courses, to be subsequently diagnosed with a congenital lung condition which is a potential contraindication to diving. Expert opinion on the fitness to dive for such individuals is also presented in this case report.An asymptomatic 26-year-old male diver was nominated to attend an overseas naval diving course. Prior to this, he had been medically certified to participate in, and had successfully completed other military and recreational diving courses. He had also completed several hyperbaric bounce dives up to a depth of 50 m (~ 164 ft) and 45 recreational dives up to a depth of 30 m (~ 98 ft). He had been well and did not have a history of diving-related injuries or complications such as decompression illness or barotrauma. He had never smoked and did not have any known medical or congenital conditions, specifically recurrent respiratory infections. There was no past surgical history, or family history of respiratory or congenital conditions.As part of pre-course screening requirements for his overseas course, a physical examination, blood tests, as well as posteroanterior (PA) and lateral Chest X-rays (CXR) were performed Figs.  and 2. TAdditional file 1: Video 1. Computed Tomography Pulmonary Angiogram, Coronal Lung Window. A Computed Tomography Pulmonary Angiogram was performed which revealed a 9.7 × 9.1 mm left lower lobe intralobar bronchopulmonary sequestration with a cavity and direct aortic supply from the descending aorta and venous drainage into the inferior left pulmonary vein. The arterial and venous vessels are highlighted in the video (red and blue arrow respectively).The diver remains asymptomatic and well at the time of writing this case report and has been accepted to participate in another overseas course involving only dry diving in a hyperbaric chamber . There are no course prerequisites for him to undergo surgery.This is the first reported case of a SCUBA diver who, having previously completed several recreational and military diving courses, was subsequently diagnosed with a congenital lung condition, possibly contraindicating diving. Identification of a systemic arterial supply via CT Pulmonary Angiography is pathognomonic, aiding diagnosis by facilitating differentiation of BPS from other congenital pulmonary diseases, and also subsequently guiding surgical management. Leoncini G et al. previously reported a case of a 29-year-old Italian man with ELS, who presented with haemoptysis and was treated with embolization. He was subsequently certified with a license to dive, but there is no documentation of his diving history prior to, and after diagnosis and treatment of his ELS .Extralobar sequestrations are separated from the normal lung by its own pleura, have a 3:1 male predominance, and are more likely to be associated with other congenital anomalies: 43% of all ELS cases compared to 17% of ILS cases . ConversPre-diving medical screening for military and recreational diving courses vary widely across countries and various organizations. Some diving courses require candidates to undergo PA and lateral CXRs, or even CT thorax examinations, while others, particularly recreational diving courses, will not require a PA CXR unless medically indicated  –8. AlthoSCUBA diving affords humankind the ability to explore the underwater realm. However, exposure to the hyperbaric environment poses unique demands on human physiology. Boyle’s law dictates that volume is inversely proportional to absolute pressure exerted on the body. As such, as pressure increases at deeper depths underwater, there is a reduction in the volume of gas-containing spaces in the body, and vice-versa. If these gas-containing spaces do not equalise with ambient pressure, tissue injury can result from the pressure differences on descent and lung barotrauma can result from overexpansion on ascent, resulting in life threatening complications such as pneumothorax, pneumomediastinum and arterial gas embolism .In view of these considerations, many international diving and hyperbaric medical societies such as the Undersea and Hyperbaric Medical Society  and the The current recommended management of BPS is contingent on two main factors –  the presAlthough BPS lacks communication with the tracheobronchial tree , 5, theyAs bronchopulmonary sequestrations (BPS) are rare and often retrocardiac in location, a high index of suspicion and radiological experience is essential to aid definitive diagnosis, which may be made with the use of adjunctive radiological tests such as lateral CXR, CT Thorax and CT Pulmonary Angiography. Identification of a systemic arterial supply is pathognomonic and differentiates BPS from other congenital pulmonary diseases. Bronchopulmonary sequestrations and all air-containing lung parenchymal lesions should be regarded as absolute contraindications to SCUBA diving, unless definitive uncomplicated surgical resection is performed.


Intramuscular myxoma is a rare benign tumor that presents as a slow-growing, deeply seated mass confined within a skeletal muscle. Histologically, these lesions most resemble umbilical cord tissue. They mostly occur in people between 40 and 70 years old, with a 57% female predilection. These tumors are very rare in children. Only one pediatric intramuscular myxoma case is reported in the literature. The goal of this study is to report the case of a 13-year-old girl who presented to our hospital emergency department in 2018 with right hip pain, elevated inflammatory markers, and fever; her initial differential diagnosis was hip septic arthritis, pelvic osteomyelitis, and pelvic abscess. A pelvic MRI revealed a well-defined enhancing round lesion in the right obturator internus muscle. The diagnosis was conformed with a CT-guided core biopsy. The patient's symptoms improved with conservative management, and she continues to be doing well 2 years later. Pediatric pelvic intramuscular myxomas are extremely rare; however, they can have a presentation that mimic a more serious condition such as hip septic arthritis, pelvic osteomyelitis, and pelvic abscess and should be considered in the differential diagnosis in a pediatric patient presenting with hip pain. From a group of 200 myxomas from various sites, 34 intramuscular myxomas (17%) were identified in his study.In 1965, Enzinger3 Since then, pediatric intramuscular myxoma has been reported in a 22-month-old girl with a myxoma in the posterior cervical triangle.1In a study that was done in 2002, intramuscular myxoma was described as rare in young people, and until that year, it has not been reported in children.6Intramuscular myxoma involving the obturator internus muscle has not been reported before, although there are reports of obturator externus muscle intramuscular myxoma.In this report, the case of a 13-year-old girl with a right obturator internus intramuscular myxoma is described, with a review of the literature.A 13-year-old girl presented to the emergency department with a 3-day history of right hip pain, associated with intermittent fever; the pain progressed to the point where she was not able to bear weight on the right lower extremity; her white blood cell, erythrocyte sedimentation rate, and C-reactive protein were elevated; rheumatological evaluation was negative, except for a positive antinuclear antibody titer of 1:160. She also reported right shoulder pain that increased with motion.She was evaluated with a hip radiograph and ultrasonography, which were normal, followed by a pelvic MRI scan with contrast, which did show a well-defined enhancing round lesion in the right obturator internus muscle without associated surrounding edema or enhancement, with a rim of fat seen at the periphery of the lesion. In addition, nonspecific edema was noted involving the symphysis pubis and the right sacroiliac joint Figures  and 2. TShe was also evaluated with a right shoulder MRI, which was positive for nonspecific mild amount of fluid and enhancement in the subacromial, subdeltoid bursa, and the rotator cuff interval, and tendinopathy of the supraspinatus tendon. Our clinical diagnosis for the shoulder was subacromial bursitis.The pediatric infectious disease team started the patient on empiric IV vancomycin. They also recommended an echocardiogram to assess for atrial myxoma; the echo was normal.Our interventional radiologist was consulted; the best approach for a CT-guided biopsy was discussed with him and with the orthopaedic oncologist. It was decided that a posterior approach would be the best in this case.Under general anesthesia, the patient was positioned in the prone position and the overlying skin was prepped and draped in a sterile fashion. The subcutaneous tissues were infiltrated with 1% lidocaine for local anesthesia. Using CT guidance, a 17-gauge introducer was advanced to the lesion, which was found to be solid, and through this, five, 18-gauge core biopsy samples were obtained. The specimens were sent for pathological examination and for culture. The pathology result was positive for myxoma. The cultures were negative.The pediatric infectious disease team discontinued the vancomycin on day 5 once all culture results were confirmed to be negative.The patient's course during hospitalization was of gradual clinical improvement, with supportive treatment that included NSAID and mobilization by the therapist. She was gradually able to ambulate with a walker and her right shoulder pain gradually improved. Based on her clinical improvement, and after a discussion with the family, a decision was made to manage the right obturator internus intramuscular myxoma with observation. She was discharged on day 7.She has not complained of right hip pain for the past 2 years since her discharge.7 used the term myxoma to describe a lesion that resembled the mucinous substance of the umbilical cord.In 1871, VirchowIntramuscular myxomas are slow-growing benign tumors; they can be painless or painful. The pain can be related to compression of surrounding structures.8 In the case of our patient, the pediatric infectious disease team attributed her elevated inflammatory markers, fever, and shoulder and hip pain to the possible systemic effect of the underlying intramuscular myxoma.Inflammatory markers can increase in the setting of myxomas, such as C-reactive protein, erythrocyte sedimentation rate, and interleukin-6.9Most musculoskeletal myxomas are intramuscular (82%) in location, occurring most often in the thigh (51%), upper arm (9%), calf (7%), and buttock (7%).10111213 The only pediatric intramuscular myxoma case reported in the literature is for a 22-month-old girl with an intramuscular myxoma in the posterior cervical triangle.1Intramuscular myxomas have been also reported in the paraspinal muscles of the back and cervical spine.The definite diagnosis of an intramuscular myxoma suspected on advanced imaging studies requires a pathologic examination, which can be obtained by an open, incisional, or excisional biopsy or with a core biopsy guided with advanced imaging. In the case of our patient, we chose a CT-guided core biopsy because of the deep location of the mass and to decrease the patient's morbidity.14Intramuscular myxomas are usually solitary, unless they are a part of the Mazabraud syndrome, which is characterized by the association of single or multiple intramuscular myxomas, with a monostotic or polyostotic form of fibrous dysplasia.15; this was excluded by the solid nature of the mass, which was noted during the CT-guided biopsy and the negative cultures. Localized neurofibroma was another possibility; they tend to affect a younger age group than intramuscular myxoma (20 to 30 years old); they are usually painless but can sometimes cause pain.2The differential diagnosis of our patient's case included an infectious etiology, such as a primary abscess of the obturator internus muscle16 Next-generation sequencing for determining GNAS mutation status on small core biopsies can facilitate the diagnosis of intramuscular myxoma and differentiate it from other tumors such as low-grade myxofibrosarcomas.18No specific laboratory test exists for intramuscular myxoma. Carbohydrate antigen 19-9, a tumor marker, has been reported to be correlated with intramuscular myxoma; however, it may also increase in multiple other malignant and benign conditions.Pediatric obturator internus intramuscular myxomas are extremely rare; however, they can have a presentation that mimic a more serious condition such as hip septic arthritis, pelvic osteomyelitis, and pelvic abscess. They should be considered in the differential diagnosis in a pediatric patient presenting with hip pain and a pelvic mass.


Liposarcoma arising from the mediastinum is rare, accounting for less than 1% of mediastinal tumors. Furthermore, a rapidly growing well-differentiated liposarcoma is extremely rare. A well-differentiated liposarcoma is usually considered a low-grade malignancy. However, we present an extremely rare case of a sclerosing variant of well-differentiated liposarcoma that grew rapidly within a year.A 77-year-old man with a giant mass in the left thoracic cavity was referred to our hospital. This mass measured about 10 cm and occupied the left-sided mediastinum on a chest radiography; however, there was no abnormal finding on the previous year’s chest radiography. Chest-enhanced computed tomography revealed a well-circumscribed 11-cm mass in the left-sided anterior mediastinum. Positron emission tomography showed accumulation of fluorodeoxyglucose uptake in this tumor . The radiological findings of computed tomography and positron emission tomography indicated that this tumor was a benign or low-grade malignancy; therefore, the chest radiographic findings were difficult to explain. To explain this discrepancy and establish the diagnosis, tumor resection was performed via left posterolateral thoracotomy. Intraoperatively, the left phrenic nerve and pericardium were adhered tightly to the tumor, so we resected them. The tumor was well-circumscribed and fibrous; therefore, the initial diagnosis was solitary fibrous tumor. However, based on its histopathological and immunohistochemical patterns, the tumor was diagnosed as a sclerosing variant of well-differentiated liposarcoma. Five years postoperatively, the patient remains alive with no evidence of disease recurrence.A well-differentiated liposarcoma is usually considered a low-grade malignancy. Nevertheless, the giant tumor in the present case appeared within 1 year. Thus, this was an extremely rare case of a sclerosing variant of well-differentiated liposarcoma with rapid growth. Primary mediastinal liposarcoma is rare, accounting for less than 0.5% of total liposarcomas and less than 0.13% of all mediastinal tumors [A 77-year-old man with a chief complaint of persistent dry cough had an abnormal giant mass on chest radiography (CR) and was referred to our hospital. There were no remarkable findings noted during the physical examination and in blood test results including tumor markers. The giant mass occupied the left-sided mediastinum on CR; however, there was no abnormal finding on the previous year’s CR Fig. a, b. CheTumor resection was performed without preoperative biopsy via left posterolateral thoracotomy for diagnosis and treatment. Median sternotomy is considered an alternative surgical approach for mediastinal tumors. In the present case, however, the hilar approach was considered necessary and posterolateral thoracotomy was selected. The tumor was located on the mediastinum and was suspected to invade the left phrenic nerve but not the vagus nerve. The tumor was resected with the left phrenic nerve, thymus, and a part of the pericardium (9.5 × 8.0 cm); therefore, we reconstructed the pericardium using an expanded polytetrafluoroethylene sheet .Grossly, the tumor measured 11.9 × 11.2 × 8.1 cm, and it was an elastic, well-circumscribed, yellowish, and grayish-white mass Fig. a. MoreovImmunohistochemical staining to determine the pathological diagnosis of the tumor was performed using the Leica Bond III automated system . Necrosis was absent, with up to 10% positivity of Ki-67  Fig. e. ImmunoBased on its histopathological and immunohistochemical patterns, the tumor was diagnosed as a sclerosing variant of WDLS. Sarcoma staging was Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade 1  well-differentiated, 2) myxoid, 3) round cell, 4) dedifferentiated, and 5) pleomorphic [ myxoid,  round ce dediffer pleomorpWe found it difficult to diagnose the tumor as WDLS on the basis of the preoperative imaging findings. Gaskin and Helms reported that thickened or nodular septa , associated nonadipose masses, prominent foci showing a high T2 signal, and prominent areas of enhancement in magnetic resonance imaging are all associated with increased risk of WDLS . AlthougTo our knowledge, there are few reports about WDLSs with rapid growth. In this case, the SUVmax, FNCLCC sarcoma grading, and MIB-1 index of the tumor were 3.3, grade 1, and up to 10%, respectively. Therefore, radiologically and histopathologically, the tumor was a low-grade malignancy. Nevertheless, this giant tumor appeared within 1 year.There are several possible reasons for the rapid growth of the tumor. First, there are several reports that low-grade WDLSs grow rapidly secondary to intratumoral hemorrhage; however, there was no such finding in this case. Second, the dedifferentiation of a WDLS relates to rapid growth . A dedifBecause the sclerosing variant of WDLS with rapid growth has not been reported, we did not consider this as a possible differential diagnosis preoperatively. Retrospectively, we realized that the sclerosing variant of WDLS with a paucity of fat is a potentially high-grade liposarcoma. These findings indicate that the sclerosing variant of WDLS should be considered in the differential diagnosis for anterior mediastinal lesions with rapid growth; the inherent implications in management and follow-up of these tumors are yet to be determined.


While extragonadal seminomas resulting in spinal cord compression are rarely reported in the literature, most have been treated with surgical decompression followed by radiation therapy. In this report, we present the unique and interesting case of a 38-year-old man who initially presented as an outpatient with a chief complaint of axial neck pain and lateral thoracic wall pain. After an extensive malignancy workup, he was diagnosed with a primary cervical spine seminoma and was treated with a C6–T1 laminectomy with posterior spinal instrumentation from C5 to T2. He has since undergone chemotherapy with cisplatin, vinblastine, and bleomycin, and at 24-month follow-up, he remains asymptomatic with no signs of recurrent disease. This is most commonly caused by metastatic disease from a primary lesion including tumors of the prostate, lung, and breast. Primary germ cell tumors of the central nervous system are uncommon, typically intramedullary, and affect the pineal region. Although extremely rare, there have been several reports of primary germinomas of the spine and therefore they should be considered in the differential diagnosis of a cervical spinal mass in a young patient.Our patient is a 38-year-old man with no significant medical history who initially presented to the outpatient clinic with a 1-month history of axial neck pain and right lateral thoracic pain. The pain was localized to the right 11th intercostal space and was exacerbated by inspiration. He reported no trauma or prior inciting event. On physical examination, he had tenderness to palpation about his posterior neck. Motor and sensory exams were within normal limits with no obvious neurologic deficit. Initial plain AP and lateral radiographs of the cervical spine were normal (Figure MRI of the cervical spine was obtained and demonstrated a nongeographic, destructive lesion in the posterior elements of the cervical spine arising from the spinous process of C7 and evidence of spinal cord compression Figure . CT scanA C6–T1 laminectomy was performed to gain access to the mass. The tumor was identified and wide en bloc resection of the mass was performed. The specimen consisted of the lesion surrounded by healthy appearing tissue Figure . Frozen 5Seminomas represent 50% of all germ cell tumors and most commonly affect white men between the ages of 20 to 40. There are approximately 4,000 new cases per year in the United States, representing a small fraction of new oncologic diagnoses. The prevalence of these tumors is greater in populations with a history of radiation exposure. Although classically found in the testes, extragonadal lesions have been described. Extragonadal seminomas represent 2% to 5% of all germ cell tumors and primarily arise from structures within the mediastinum, retroperitoneum, and pineal gland. Within the mediastinum, primary extragonadal seminomas have been found to arise from cardiovascular and pulmonary structures.6 Most commonly, seminomas metastasize via the lymphatic system to the viscera such as the lungs. Although rare, both metastatic seminomas and primary extragonadal seminomas can involve the spine and result in spinal cord compression.7Patients with primary testicular seminomas typically present with a painless testicular mass. At the time of diagnosis, 80% of these patients have disease limited to the testes without evidence of metastasis. The treatment of primary testicular seminomas includes resection and radiation therapy. With orchiectomy and radiation therapy, patients can expect cure rates up to 99% without recurrence.7 reported 2 cases of thoracic spinal metastases. The first describes a 33-year-old man who had previously undergone right inguinal orchiectomy and was under surveillance for recurrence. The patient developed metastases to the spine and suffered a pathologic T12 burst fracture requiring decompression and fusion from T10 to L2. The second case describes a 44-year-old man who presented with back pain and lower extremity weakness. He was found to have metastatic lesions to T4 and T5 with spinal cord compression. After left inguinal orchidectomy, combination cisplatin, etoposide, and bleomycin chemotherapy, external beam radiation therapy, his motor function and sensation improved. He did not require surgical decompression. Ng et al.8 reported a third case of spinal cord compression due to recurrent metastatic testicular seminoma. The authors described a case of a 38-year-old man who presented 14 months' status post right inguinal orchiectomy with back pain, lower extremity weakness, and acute urinary retention. He underwent posterior decompression from T7 to T9 and posterior instrumentation from T6 to T11. He regained full neurological function postoperatively. Chiba et al9 also reported a case of a patient who developed gait disturbances secondary to metastatic seminoma 6 years after radical orchiectomy. The patient was found to have a new T8 lesion on routine surveillance and experienced full recovery of his symptoms after surgical decompression and fusion.Four cases of spinal cord compression due to metastasis from a primary testicular seminoma have been previously reported in the literature. Yee et al7 In a case series of 48 patients with primary extragonadal germ cell tumors, 27 arose from the central nervous system, 16 from the mediastinum, and 5 from the retroperitoneum, none of which presented with spinal cord compression.10 Another case series of extragonadal manifestations of seminomas in the head and neck area included 16 patients, but none involved the cervical spine or resulted in spinal compression.11 There was one case of spinal cord compression due to a primary posterior mediastinal germ cell tumor reported in the literature in a 7-year-old boy. The mass extended from T5 to T11 with involvement of the vertebral bodies of T8–T9. The patient was treated with total laminectomy from T6 to T10 with postoperative bracing treatment. The patient recovered postoperatively with mild kyphotic curvature and 4/5 strength in his lower extremities at 3 years postoperatively.12In patients with primary retroperitoneal and mediastinal seminomas, extensive mass effect and destruction of the anterior spinal elements must occur before spinal cord compression results.13 30 primary intradural spinal germinomas were reported, only 13% of which were purely extramedullary. All four of the cases of primary extramedullary spinal germinomas were intradural, requiring posterior laminectomy and durotomy to access the lesions, and careful and extensive dissection of the tumor from the nerve roots with variable clinical success (Table 14 A second case describes a 28-year-old man who died secondary to the cardiopulmonary complications of transverse myelitis from ascending metastases to the cervical spine.5 Finally, two case reports, one of a 43-year-old man and another of a 20-year-old woman, describe near full neurologic recovery after posterior decompression and dissection of the nerve roots.15Primary spinal germinomas have also been described although they typically arise from the medulla of the spinal cord itself. In a literature review by Loya et al,To the best of our knowledge, this is the first report of a primary extragonadal, extradural seminoma in the posterior elements of the cervical spine. This highlights the importance of the unique location of the tumor, which presents a diagnostic challenge as to the identity of the tumor prior to biopsy. Surgical management is also dependent on the location of the tumor because durotomy was not required to access our patient's tumor due to its extradural nature. Certainly, it is imperative to do a thorough oncologic workup before surgical resection. If a primary seminoma is identified, primary resection followed by an oncological consultation should be highly considered because previous case reports have supported the benefits of surgical decompression and subsequent radiation and chemotherapy.


Osgood-Schlatter disease is a traction apophysitis of the tibial insertion of the patellar tendon. It consists one of the most common causes of knee pain in adolescents and usually presents in young males and it is considered a self-limiting condition. Although the symptoms disappear after the closure of the growth plate in most cases, in some patients they may persist. A variety of conservative treatments are used in most cases, however surgical intervention can be successful for patients who have intolerable symptoms. Most surgical options of the Osgood-Schlatter disease include open procedures, while arthroscopic or direct bursoscopic excision has been reported. We believe that the arthroscopic removal of an unresolved Osgood-Schlatter might be the most appropriate treatment for this condition, and we present a case of a male patient with an ununited ossicle due to an Osgood-Schlatter lesion, which was removed arthroscopically using a multidirectional arthroscope and a motorized semi-hooded barrel burr. Osgood-Schlatter disease was first described in 1903 and is a traction apophysitis of the tibial insertion of the patellar tendon caused by the repetitive strain on the quadriceps femoris muscle -5.In most cases conservative treatments, which include rest, lidocaine injection, steroid injection, cylinder casts and infrapatellar straps, are adequate . HoweverHereby we report a case of a male patient with an ununited ossicle due to an Osgood-Schlatter lesion, which was removed arthroscopically using a multidirectional arthroscope and a motorized semi-hooded barrel burr.A 26-year-old, male semiprofessional soccer player had a prominence of tibial tuberosity for 10 years and reported anterior knee pain during sports activity and while climbing stairs. He claims pain commencement about 15 years ago and since then he mentions occasional pain episodes. He underwent conservative treatment for the last two years with anti-inflammatory drugs and physiotherapy and he had three injections of corticosteroids at different times. On physical examination, there was a permanent tibial tubercle with pain during palpation Figure . DimensiDiagnostic arthroscopy was performed using a low anterolateral portal close to patellar tendon Figure . The intPostoperatively, instructions for partial weight bearing and isometric flexion extension 0°-90° exercises for two weeks were given. After two weeks walking without crutches was allowed while no squatting for six weeks was suggested. After two months, the patient returned to sport activities without any restrictions and complaints. Postoperative X-ray showed minimal ossicle residual, and clinically there was no prominence Figures .Although the natural history of Osgood-Schlatter lesions is that most resolve and it is usually considered to be self-limited, some patients may still have some pain and prominence with kneeling . Krause However, if conservative treatment fails, operative treatment may be considered. There are surgical procedures that include drilling of the tubercle, removal of the loose fragments, autogenous bone peg insertion through the tubercle, tibial tuberosity excision, or sequestrectomy . FurtherIn the case presented here, the use of multidirectional camera provided excellent view of the ossicle while its localization with a needle proved extremely helpful. The use of the assisting low anterolateral portal and of the motorized semi-hooded barrel burr provided an easy and rapid removal of the larger part of the bony lesion. We believe that the arthroscopic removal of an unresolved Osgood-Schlatter lesion showed excellent results and might be the most appropriate treatment for this condition.


Glandular odontogenic cyst is a rare developmental odontogenic cyst that bears similarity to several other odontogenic lesions. Till 2017, only 169 such cases have been reported in the literature. Herein, we describe one more case of it occurring in a 35‐year‐old female patient. Glandular odontogenic cyst is a rare developmental odontogenic cyst that bears similarity to several other odontogenic lesions. Till 2017, only 169 such cases have been reported in the literature. Herein, we describe one more case of it occurring in a 35‐year‐old female patient. On clinical examination, hard swelling was present on left body of mandible in relation to 36 and 37, obliterating the buccal vestibule and measuring about 1.5 cm in diameter. On palpation, the lesion was nontender, with no discharge, and the overlying mucosa was normal.Radiographic examination revealed a well‐defined unilocular radiolucency involving the body of mandible in relation to the apices of 36 with well‐defined corticated borders measuring 22.5 mm × 15.5 mm. Tooth numbers 35, 36, and 38 were nonvital, and 37 was missing Figure . PAS sta3Glandular odontogenic cyst is a rare developmental odontogenic cyst accounting for about 0.012% to 1.3% of all jaw cysts.The lesion is usually asymptomatic,As both clinical and radiological features of GOC are deceptive, histopathological examination of the lesion becomes crucial to arrive at the final diagnosis. However, this also poses a diagnostic challenge, as its histopathological features resemble other lesions such as lateral periodontal cyst (LPC), botryoid odontogenic cyst (BOC), and central mucoepidermoid carcinoma (CMEC). Several authors have put forward the microscopic criteria's for diagnosing of GOC. Kaplan et al established major and minor criteria for diagnosis of GOC, whereas Fowler et al proposed ten specific microscopic features and suggested that the presence of seven or more of these features are highly predictive of GOC.The treatment modalities of GOC include enucleation with or without curettage, marsupialization, peripheral ostectomy, chemical cauterization with carnoy's solution, and marginal or segmental resection.4Glandular odontogenic cyst is a rare odontogenic cyst that has aggressive clinical behavior and high rate of recurrence. Due to its nonspecific clinico‐radiographic features, it is often misdiagnosed. Hence, careful histopathological evaluation is necessary for final diagnosis along with the long‐term follow‐up to rule out the recurrences.None declared.Informed consent was obtained from the patient for publication of the case.PP: is a primary author, prepared, structured, and formatted case report. RS, NC, and CU: critically reviewed the manuscript.


Retroperitoneum is an uncommon site for Schwannoma tumors and among adrenal incidentaloma the Schwannoma is rare. This condition lacks of a specific clinical and radiological features, but correct diagnosis before pathological examination should be very important for clinical management and surgical decision. We describe a case of voluminous retroperitoneal incidental mass, that was proved to be an adrenal Schwannoma. Schwannomas arise from Schwann cells, so they can appear in any portion of neural tissue where cells of Schwann are present but they prefer neck and head regions or the flexor surfaces of the upper and lower extremities.19,20 makes difficult to diagnose adrenal Schwannomas as other malignant tumors of adrenal glands or retroperitoneal organs.4,8,21A correct pre-operative diagnosis of adrenal Schwannoma is essential to avoiding unnecessary extensive surgery and/or regional lymph nodes dissection; in routine clinical practice, the lack of specific clinical and radiological featuresT1 weighted images and heterogeneously high signal intensity on T2 weighted images, with progressive contrast enhancement after contrast medium injection and without drop of signal in T1 weighted opposition phase sequence. The tumors showed mild and progressive peripheral enhancement involving especially the wall and the internal septa with irregular pattern due to cystic intralesional components  was performed to characterize the mass: a voluminous solid and heterogeneous mass with fluid components was detected in the left adrenal gland. The mass measured 9 × 6 × 7 cm and showed low signal intensity on mponents . The adrmponents . Unenhanmponents . The rigmponents . After amponents . Gross e13 Firstly Schwannomas were described by Verocay in 1908 and Antonini in 1920 subclassified these tumors into two distinct histologic patterns.22 Typical Schwannoma is a solitary mass, with ovoid or spherical morphology and well-defined margins; when Schwannoma is very large (>8–10 cm) it is frequently affected by degenerative changes with cystic areas, calcifications, interstitial fibrosis and hyalinization. The degenerative pattern is predominant in the “ancient” Schwannoma, a variant with a very good clinical outcome.23 It should be known that 5–18% of Schwannomas are associated with von Recklinghausen’s disease; in this pathological context Schwannomas are generally malignant with a trend of manifestation in multiple areas.24 The medulla of adrenal gland receives double innervation by two different groups of myelinated nerve fibers, respectively derived from the sympathetic trunk (or vagus nerve) and from the phrenic nerve. Adrenal Shwannomas are thought to origin from one of those nerves and to arise from medulla because of the uninterrupted continuance between the tumor and the adrenal medulla in absence of septum around the tumor. They grow up from adrenomedullary site compressing the adrenal cortex.16 Schwannomas present two main microscopic pattern at histological analysis, that are respectively characterized by high cellularity component (areas of Antoni A) and pure myxoid component (areas of Antoni B). Each component may result prevalent in the lesion determining a specular radiological specific findings on CT or MRI scans. Morever, as tumors with neuroectodermal origin, almost all Schwannomas exhibit intense immunohistochemical staining for S-100 protein.13,25 A limited number of Shwannomas may be not easily distinguishable from neurofibromas because of their similar histologic aspects and positive staining for S-100 protein.14 Moreover, in the assessment of differential diagnosis between these two entities, Fine et al26 have demonstrated that a positive stain for calretinin  helps for discrimination and allows a diagnosis of Shwannoma. Behavior of these tumors may be biologically benign or not. Malignant Schwannomas are often ex-novo lesions, with locally invasive pattern of growth and tendency to develop distant metastases.25 On the contrary, benign lesions do not present invasive trend and during expansion they simply displace surrounding structures and organs; however, there is not proven correlation between size and biological malignant potential.27 One percent of all retroperitoneal tumors are Schwannomas and only 1–3% of all Schwannomas are located in profound structure such as retroperitoneum and posterior mediastinum, representing uncommon siting of this tumor.28,29 Retroperitoneum is a flexible space and Schwannomas detection is often accidental because large size can be reached before they become symptomatic, showing for long time only incipient and vague sign of adjacent organ compression. In advanced stages, space-occupying mass signs manifest with lumbar heaviness or pain, neuralgia and paresthesia in the distribution of the affected nerves, ureteral obstruction; in malignant forms with infiltration of surrounding structures there are generally hematuria and bone pain.27 The insufficiency of specific or typical imaging findings on ultrasound, CT or MRI makes the pre-operative diagnosis and the differential diagnosis with other retroperitoneal malignant entity very difficult.30 However, the role of radiological imaging is essential in management and treatment planning through examination of tumor size, location, possible invasion of other structures.13,31 In accordance with literature, at MRI the Shwannomas show low signal intensity on T1 weighted images and heterogeneous high signal intensity on T2 weighted images with cystic areas and smooth profile. However, these imaging characteristics are not specific. Our tumor showed regular margins, heterogeneously high signal intensity on T2 weighted images, described as necrotic components, and small areas of degeneration on histological examination were present. Most of the head and neck schwannomas are characterized by typical appearance of free diffusion in the centre and restricted diffusion in the periphery of the mass.32 In our case, there was not this evidence. Infact, myxoid matrix, abundant in Schwannomas , is composed by elevated water content, due to poor cellularity, high mucin and low collagen content, and this likely explain their high diffusivity.33 Previous studies described the apparent diffusion coefficient (ADC) values of some adrenal lesions concluding that ADC values could not be used to differentiate between benign and malignant lesions;34 in the differential diagnosis between paragangliomas and schwannomas the ADC quantitative assessment could not provide significantly for the differentiation of both tumors.35 Classic CT findings of retroperitoneal Schwannomas are rounded and well-marginated masses with various enhancements. Adrenal Schwannomas are hypovascular tumors with mild heterogeneous and delayed progressive enhancement pattern involving equally the tissue, the septa and the walls of the lesion; however, the presence of degenerative changes contributes to make more heterogeneous the enhancement.31 The intravenous contrast medium injection should facilitate the differentiation with the adrenocortical carcinoma, characterized by rapid enhancement in hepatic arterial phase, and with pheochromocytoma, which generally is an hypervascular lesion with significant early heterogeneous enhancement.31 Calcifications and cystic components are frequently identified in these tumors.11,12,31 In our case, unenhanced CT performed during FDG CT-PET examination confirmed the presence of well-circumscribed round mass without evidence of calcifications. Cystic-like areas were visible and also detected trough small region of interest placement. The mass showed also an increased FDG uptake. Non-functioning solid tumors represent the main differential diagnoses of adrenal Schwannoma, which is not easily distinguishable from adrenal adenoma, adrenal myelolipoma, groups of neuroblastomas , adrenocortical carcinoma and adrenal metastasis. Adrenal adenomas and adrenal myelolipomas generally have a fat content that makes possible to differentiate them from other tumors. Neuroblastomas are positive during metaiodobenzylguanidine (MIBG) scintigraphy in seventy percent of cases and, among the neuroblastomas, ganglioneuromas are similar to retroperitoneal Schwannomas on imaging studies. However, although MIBG-negative ganglioneuromas are difficult to differentiate from Schwannomas36 , Ichikawa et al described delayed heterogeneous enhancement of ganglioneuroma on contrast- enhanced CT and whorled appearance with curvilinear bands of low signal intensity on T2 weighted images on MRI.36 Radiologist should keep in mind these findings that could be helpful in the differential diagnosis between MIBG-negative ganglioneuromas and other tumors. In our experience, the preoperative diagnosis was erroneous and misinterpreted the nature of the lesion, suggesting the possibility to be facing an adrenal ganglioneuroma or pheochromocytoma. Our experience confirms the difficulties in obtaining a correct diagnosis before pathological examination.Schwannoma is a neurogenic tumor, generally occuring between the third and the sixth decades of life, with no sex or location predilection. In fact, it may arise everywhere in organs or nerve trunks and the with sole exception of cranial nerves I and II, lacking Schwann cells.In summary, primary adrenal Schwannomas are rare and difficult to diagnose and frequently pre-operative workup is non-diagnostic, only postulating a non-secreting adrenal mass.For this reason, adrenal Schwannomas should be always included in the differential diagnosis of solid nonfunctioning adrenal tumors.T1 weighted images and heterogeneous high signal intensity on T2 weighted images.MRI is a valuable imaging technique for the diagnosis of adrenal Schwannoma, which appears as a well-circumscribed unilateral mass with cystic degenerative changes, characterized by low signal intensity on As confirmed by literature and by our experience, radical excision must be considered the most appropriate treatment, resulting in satisfactory prognosis.Given the rarity of this tumor and lack of definitive nonhistologic diagnostic modalities, adrenal Schwannoma remains a diagnosis of exclusion, but it should occupy an important place in the differential diagnosis set of incidentally discovered adrenal masses, as illustrated by this case.


Susceptibility to diseases is common to humans and dinosaurs. Since much of the biological history of every living creature is shaped by its diseases, recognizing them in fossilized bone can furnish us with important information on dinosaurs’ physiology and anatomy, as well as on their daily activities and surrounding environment. In the present study, we examined the vertebrae of two humans from skeletal collections with Langerhans Cell Histiocytosis (LCH), a benign osteolytic tumor-like disorder involving mainly the skeleton; they were diagnosed in life, along with two hadrosaur vertebrae with an apparent lesion. Macroscopic and microscopic analyses of the hadrosaur vertebrae were compared to human LCH and to other pathologies observed via an extensive pathological survey of a human skeletal collection, as well as a three-dimensional reconstruction of the lesion and its associated blood vessels from a µCT scan. The hadrosaur pathology findings were indistinguishable from those of humans with LCH, supporting that diagnosis. This report suggests that hadrosaurids had suffered from larger variety of pathologies than previously reported. Furthermore, it seems that LCH may be independent of phylogeny. Neoplasms (cancer), albeit more difficult to diagnose , have also been identified in dinosaurs5. Disease occurrence in dinosaurs is very infrequent. When present, however, it can tell us about dinosaurs’ immune systems, metabolic disorders, growth and adaptation to a huge body mass, infections, environment, as well as shed light on their mating patterns and hunting techniques.Understanding diseases that affected dinosaurs may shed additional light on their biology, daily living, and the environments in which they thrived. Despite the huge time gap between dinosaurs and humans, both were susceptible to diseases that shaped and greatly affected their evolutionary history. Thus, recognition of skeletal manifestations of specific diseases in humans may assist in identifying them in dinosaurs as well. For example, gout was recognized in tyrannosauridsGryposaurus and Prosaurolophus as well as the crested Corythosaurus and Lambeosaurus are the most common. Trauma, in the form of healing caudal vertebrae , rib fractures, and osteochondrosis of the pedal phalanges, predominate. Fusions of dorsal and caudal vertebrae are also known to occur. A literature review of the entire Hadrosauridae family appears in Tanke and Rothschild6, with reviews and specific case studies of Albertan material appearing in Rothschild and Tanke7, Straight et al.8, Tanke and Rothschild7, and Tumarkin et al.9. Other Albertan hadrosaur-centric studies are currently underway.Herbivorous hadrosaurs, also referred to as “duck-billed” dinosaurs, have a near-global Late Cretaceous fossil record. They reached a length of over ten meters, weighed several tons, and appear to have lived in large herds. They are particularly well-known in southern Alberta, Canada where individual bones and teeth occur in abundance. In addition, several dozen hadrosaur-dominated bonebeds and hundreds of partial-to-complete skeletons have been discovered. In Dinosaur Provincial Park, examples of hadrosaur osteopathy are so common that more than half a dozen examples can be found daily by an experienced field worker. A number of hadrosaur taxa are known from the Park: the cranially uncrested 11; it is the most common of the non-infectious granulomatous bone disorders13. Histiocytosis is the clonal result of neoplastic mutation and proliferation of hematopoietic stem cell precursors of tissue-resident mononuclear phagocytes (histiocytes) or of precursor dendritic cells17. Mononuclear phagocytes can be divided into two groups: a monocyte-macrophage group (Erdheim-Chester disease), and a Langerhans (dendritic) cell group20. The latter group normally functions as antigen processors in the immune system. Since Erdheim-Chester disease produces osteosclerotic lesions21, in contrast to the lytic lesions of LCH, it will not be further discussed here.Langerhans Cell Histiocytosis (LCH) is a benign osteolytic tumor-like bone lesion that is commonly manifested in the skeletal system in either a unifocal or multifocal form23. Two other syndromes, which are considered as the same disease, yet are less common (up to 20% of cases in children), are the Hand–Schuller–Christian and the Letterer–Siwe diseases. The first includes skull lesions, exophthalmos, and diabetes insipidus; the second includes disseminated lesions involving multiple visceral organs23.The most common form of LCH, eosinophilic granuloma, is an isolated bone lesion, most commonly afflicting children and adolescents (between ages 5 and 10), with a slight bias toward males13. Some consider it a disorder of the immune system , possibly of viral and other infectious causes , or a neoplasia, after identifying clonal proliferation of cells and after its response to chemotherapeutic treatment27. Advancements in sequencing technology enabled the pathophysiology of LCH to be identified and revealed its association with a genetic mutation (mainly in BRAF or MAP2K1 genes), resulting in MAPK hyperactivation of myeloid precursor cells28 (and references therein).Although LCH was first described in humans by Thomas Smith in 1865, its etiology and pathophysiology have been debated for many years30. It usually appears as a solitary lesion involving the vertebral bodies of the thoracic vertebrae, followed by the lumbar and cervical regions of the spine34. LCH clinical manifestation varies: it can be asymptomatic and discovered as an incidental radiographic finding, or it can be symptomatic with pain, swelling, and tenderness around the lesion. The most common symptoms include neck or back pain, restricted motion of the spine, neurologic symptoms, and deformity11. Differential diagnosis includes Ewing sarcoma, osteomyelitis, metastases, round cell tumor, lymphoma, and leukemia23.LCH usually appears in the skull, followed by the femur, mandible, pelvis, spine, and ribs. Radiological features of the lesion vary between skeletal parts. For example, in the skull, it appears as a solitary or multiple punched-out lytic lesion without a sclerotic rim, whereas long bones exhibit endosteal scalloping and periosteal reaction. Spinal eosinophilic granuloma accounts for 6.5% to 25% of all skeletal LCH cases35, examination of isolated elements usually does not allow discrimination, and diagnosis of lytic lesions has been especially problematic37. Nevertheless, some diseases have reproducible differences in skeletal expression, e.g., metastatic cancer, tuberculosis, fungal disease, and as those documented in the current study, which enable distinguishing between them38. All forms of LCH in clinical cases are diagnosed through bone marrow aspirates or biopsies of lesions. The samples obtained are then tested for the presence of the Langerhans cell phenotype, using immune-histochemical staining or electron microscopy23. Unfortunately, loss of soft tissues through taphonomic processes in the dinosaurs and through defleshing processes in recent humans precluded applying such immunohistologic methodology at this time, since pertinent soft tissues  are usually not preserved39.Recognition of disease in the fossil record is challenging. Although patterns of disease have proven diagnostic 43. The absence of previous reports of non-infectious granulomatous bone disorders in the fossil record may be related to difficulties in distinguishing these disorders from other bone tumors due to meager detailed macroscopic descriptions44 as the differences between the various lesions are below the resolution of routine radiological techniques, e.g., plain radiographs and CT35. Therefore, systematic surveys of skeletal collections for pathologies whose clinical records are available enables recognizing the apparent uniqueness of lesions and tumors such as granulomatous diseases, and creates a standard for their identification in the archaeological and paleontological records.Non-infectious granulomatous bone disorders have rarely been mentioned as a possibility in the anthropological literature45. However, these lesions were indistinguishable from those noted in a human with clinically documented LCH.A search for pathologies in paleontological skeletal collections revealed unique lesions in a hadrosaur, which differed in character from what we had previously observed in individuals (both human and non-human) with cancer and bone tumorsThe aim of the current study was to provide the most reasonable diagnosis for the lesions observed in the hadrosaur vertebrae, considering diagnostic criteria based on a systematic pathological survey of the Terry skeletal collection.th century; it is housed in the U.S. National Museum of Natural History, the Smithsonian, Washington D.C. The second is the Galler Collection, a pathology reference series dating from the mid-19th through the mid-20th century from the Institute of Evolutionary Medicine, Zurich University; it is housed in the Natural History Museum Basel, Switzerland. A fundamental difference between the Terry and Galler collections should be noted: The former consists of the entire skeleton, whereas the latter generally includes only macroscopically recognized pathological elements. The individual from the Terry collection is a 19-year-old African American male, and the individual from the Galler collection is a 3.5-year-old male (#1328/55).Two individuals who were diagnosed in life with LCH  were included in this study. Both originate from skeletal collections: one is the Terry Collection, which consists mainly of individuals from the St. Louis, Missouri area, who died during the first half of the 20In addition, a systematic survey of the Terry Collection was carried out to identify which bones are most commonly affected in different pathologies . The authors received permission to study these human specimens.3. The larger of the two . Of these distal caudal hadrosaur centra, two pathologic vertebrae were identified Fig.  is 40.2 two Fig.  is 53.2 Information on the pathologies of the studied samples was obtained from their medical files as well as via macroscopic observation of the pathological bones.www.fei.com) software. Segmentation was achieved using various semi-automatic tools to reconstruct the 3D mesh surfaces of the tumor, blood vessels, and bone surface. The vertebrae and mass-occupied areas were measured after segmentation.Preliminary identification of the pathological vertebrae was carried out macroscopically and via epi-illumination microscopy at 20-200x magnification on articular surfaces using a white light-emitting diode (LED) Dino-lite digital microscope . To verify the pathology, the vertebrae were scanned via a microfocus X-ray computed tomography system , operated using a 225 kV 225 W reflection target utilizing the following scan parameters: 50 μm, 182 kV, 124 μA, at the Shmunis Family Anthropology Institute, Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University. The scan volume was reconstructed using NM CT reconstruction software  and exported in a 16-bit tagged image file format (TIFF). Segmentation and analyses of the vertebrae and the tumors were carried out using Amira  to obtain an appropriate depth of field.The dinosaur vertebrae were also photographed at 40x magnification using a stereo microscope  equipped with a digital camera  at the Department of Anatomy and Anthropology, Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University. Image stacks were acquired and processed with the Extended Depth-of-Focus module in NIS-Elements BR software  revealed geographic vertebral defects, smooth-walled, with multiple smooth extensions. Serpentine, smooth-bordered erosions with “wrinkled” bases, gave the impression of a “space-occupying mass.” Subjacent trabeculae were effaced, with no evidence of new bone formation or “blunting” Fig. . HoweverMicroscopic examination revealed a clear “zone of transition” Fig.  between 3, occupying 4% of the total volume of the vertebra. The smaller mass was 11.4 mm in height, 21.0 mm in breadth, and 17.7 in length, The total volume of this tumor was 2440 mm3, occupying 7.4% of the total volume of the vertebra.The 3D reconstruction of the cavity revealed the presence of a space-occupying mass at the center of the vertebral bodies. The mass, generally spheroidal in shape, nevertheless possesses numerous extensions of varying size. Many blood vessels reach the mass, some directly via the basivertebral opening Fig. . Lesions47 nor the first report of tumor/tumor-like pathology in dinosaurs49. Hadrosaurs were unique among dinosaurs regarding their susceptibility to neoplastic processes, both benign and malignant48. Nevertheless, this study is the first to suggest a case of LCH in the fossil record, and the first to provide evidence-based criteria  for its recognition in skeletons, when soft tissue structures cannot be assessed. We feel confident in comparing the appearance of LCH in humans and dinosaurs, since monocytes and lymphocytes (in contrast to erythrocytes and neutrophils) of reptiles and birds have morphology and function similar to those of mammals52.This is neither the first report of LCH in a veterinary record53. Spinal involvement by LCH mainly affects thoracic vertebral bodies (centra), sometimes resulting in anterior wedging or a near collapse, with a “vertebra plana” appearance. Posterior elements are rarely involved54. This pattern of vertebral involvement is noted in Terry #129 and Galler 1328/55, as well as TMP 2011.012.04207. The coalescence of multiple lesions (thus creating the “geographic” appearance)57, as well as the “space-occupying masses” and effaced trabeculae  appear to reproducibly define LCH; they were present in Terry #129 and Galler 1328/55, as well as TMP 2011.012.0420. These characteristics are also notable in MRI images of a vertebra of a 47-year-old male who was diagnosed with LCH58.LCH produces well-defined, eccentrically shaped lytic bone defects60, and have not been observed in any other lytic process.An apparently unique feature is effaced trabeculae, occasionally with wrinkled bases. The lesions were different in appearance from those seen in metastatic cancer, tuberculosis, and fungal disease61. Schmorl’s nodes are not included in the differential diagnosis for two main reasons: (1) They expand into vertebral endplates from the disk space rather than expanding from the vertebral body center outward through the surface, as observed in our case. (2) Hadrosaurs do not have intervertebral disks; their vertebral centra articulations are synovial lined joints62.Differential diagnosis (other diagnostic considerations) of LCH includes tuberculosis, fungal disease, brucellosis, echinococcosis (dog tapeworm), metastatic cancer, multiple myeloma, lymphoma, leukemia, hyperparathyroidism, osteomyelitis, and bone tumors Table 23,61. ScBone destruction with well-defined margins is generally a sign of a relatively benign process. The important characteristic is the so-called “zone of transition” between normal and abnormal bone. Benign processes tend to have a very sharp or thin “zone of transition.” Less well-demarcated “zones of transition” are more characteristic of malignant bone tumors and infectious diseases.63. The most characteristic aspect of lytic lesions in tuberculosis is the presence of smooth “zones of resorption”. This is in contrast to the “space-occupying mass” appearance noted in LCH. The appearance of LCH also differs from the “fronts of resorption” perforated by blunt 1 × 2-mm spicules of new bone, apparently characteristic of fungal disease56. Brucellosis produces a very characteristic anterior vertebral articulating surface groove35. Echinococcal hydatid cysts produce expansile lytic lesions with small cystic outpocketing61. Subchondral  cysts are neither multilocular nor multilevel phenomena, and do not have a “geographic” appearance61.While LCH may invade a joint by contiguous growth, tuberculosis is predominantly a disease of joints73.Among bone tumors affecting the vertebra, LCH can be distinguished from: the expansile, soap bubble appearance of aneurysmal bone cysts that have thin, eggshell-like bony margins that predominantly affect posterior elements of vertebrae; the radiolucent nidus of osteoid osteoma; the large expansile lytic metaphyseal lesions of osteoblastomas; the solitary, vertebral nature of giant cell tumors  and chondroblastoma that demonstrate epiphyseal popcorn-shaped calcification characteristics of the latter; the non-ossifying and desmoplastic fibromas ; the ground glass appearance of fibrous dysplasia ; the ill-defined margins of Ewing sarcoma and osteosarcoma, which usually do not affect vertebrae; the vascular tumors , which may be bubbly or have characteristic linear residual trabeculae; and the lipid cell tumors, which are lobulated and have internal bridging61. While most are highly characteristic, “brown tumors” of that disease may cause confusion. Recognized radiologically, they are internal osseous processes, which would not be anticipated as a source of confusion with the surface lytic processes of LCH. Furthermore, osteoclast-based resorption (characteristic of brown tumors) produces “fronts of resorption”74, not “space occupying masses” (characteristic of LCH).Hyperparathyroidism rarely produces skeletal alterations61, the presence of a wrinkled base appears to be specific for LCH.The absence of remodeled trabeculae and of the buttressing of subjacent trabeculae appear to distinguish the lesions of LCH from those of metastatic cancer (characterized by trabecular remodeling and buttressing). Although discrete lytic lesions in individuals with metastatic cancer have the “space occupying” appearance72. Although “vertebra plana” can occur with Ewing’s sarcoma, the lesion is more aggressive and ragged in appearance, in contrast to the “space occupying mass” appearance of LCH.Poorly demarcated “zones of transition,” with borders merging imperceptibly with the surrounding healthy bone, are found in Ewing’s sarcoma, often associated with a laminated or with a “hair-on-end” periosteal reaction1. An “onion-skin” type of periosteal lamination may be present75, contrary to what is noted in LCH. Multiple myeloma may produce a “space occupying mass” appearance, but it is uniquely expansile, penetrating cortical as well as trabecular bone. This results in a fully spherical appearance76, contrary to observations in LCH.Solid tumors of white blood cells  produce a permeative or “moth-eaten” appearance, eventually disrupting the cortex78, it is a very different disorder from the benign process of LCH that most probably affected the hadrosaur in the current paper. There are, however, reports of LCH in tigers Panthera tigris)47 and a tree shrew (Tupaia belangeri)46.Whereas malignant histiocytosis is reported as an aggressive disease in the veterinary literature for dogs and catsBased on our radiographic analysis of the hadroseaur vertebrae and the extensive comparison with various human pathologies, we suggest that this case is the first LCH disease recognized in a dinosaur. This report extends the spectrum of pathological processes with which these denizens of the Cretaceous Period were afflicted, and suggests that pathological processes are independent of phylogeny and time.