The GI stromal tumor is better known as GIST, positive CD117, ckit, PDGF, manual.

A 60-year-old man with abdominal pain and upper gastrointestinal bleeding was found to have an abdominal tumor related to the gastric wall. Histology shows a spindle cell tumor with few mitoses, positive for CD117. The most likely diagnosis is:

[Gastric stromal tumor with myxoid degeneration. Report of a case and review of the literature].

Gastrointestinal stromal tumors (GIST's) represent a heterogeneous group of neoplasms that have as their common histologic denominator an immature proliferation of epithelioid or spindle cells. Although originally believed to represent atypical variants of leiomyoma or leiomyosarcoma, recent studies have demonstrated that only a subset of such tumors actually display well developed immunohistochemical, ultrastructural features of smooth muscle differentiation. Most gastrointestinal mesenchymal tumors are of uncertain histogenesis. Current studies have shown a striking morphological and immunophenotypic similarities of these tumors with the interstitial cells of Cajal. And that they may originate from stem cells that differentiate toward a pacemaker cell phenotype. Most GIST's have a co-expression of Kit (CD117) or CD34, which is also express in interstitial cells of Cajal. This review will attempt to summarize the current knowledge and understanding of these lesions based on review of the literature, with an analysis of the criteria for distinguishing between benign and malignant tumors. We report a Gastrointestinal Stromal Tumor of the stomach with prominent cystic degeneration. The patient had diarrhea, abdominal pain and was found to have abdominal mass. X-ray and computed axial tomography examination showed a lesion that seems to be a pancreatic cystic lesion. At laparotomy a large intramural tumor located in the stomach was found. Histologically, the lesion was composed of epithelioid and spindle cells embedded in an abundant myxoid stroma. Tumor cells showed positive staining for vimentin and CD34 positive. We conclude that the diagnosis of gastrointestinal stromal tumor whit prominent cystic degeneration can be made in this case.

Rupture of gastrointestinal stromal tumor presenting with sudden onset chest and back pain and accompanied by gastric dilatation.

A 72-year-old man with hypertension was admitted with acute-onset chest and back pain followed by epigastralgia. He was transported by helicopter due to suspected acute aortic dissection. Systolic blood pressures were equal in both arms. Physical examination showed epigastric tenderness without rebound. Blood tests showed leukocytosis. Electrocardiogram and echocardiogram were normal. Abdominal radiography showed acute gastric dilatation with an air-outlined large mass-like shadow. Abdominal computed tomography revealed a 6-cm exophytic mass and large intramural hematoma in the lesser curvature of the gastric body. The patient underwent urgent laparotomy with total gastrectomy. The resected tumor showed positivity for CD117 and CD34 but negativity for S100, indicating a gastrointestinal stromal tumor. Fourteen days after the surgery, the patient was uneventfully discharged. Intramural bleeding of submucosal tumors including gastrointestinal stromal tumor should be considered in cases of acute gastric dilatation. Abdominal radiography may be a clue regarding the presence of this condition.

[A Case of Spindle Cell Tumor in the Gastric Mucosa Treated with Laparoscopic Local Gastrectomy].

The patient was a 43-year-old man. An upper gastrointestinal endoscopic examination revealed a gastric submucosal tumor(SMT)-like, elevated 8-mm lesion in the greater curvature of the upper body of the stomach. It was diagnosed as spindle cell tumor on the basis of biopsy findings, and a gastrointestinal stromal tumor(GIST)was suspected. Various immunohistochemical staining techniques were used; however, a definitive diagnosis could not be achieved. There was no evidence of distant metastasis even on thoracoabdominal computed tomography imaging; thus, the patient was referred to our department for definitive diagnosis and surgical treatment. Laparoscopic local gastrectomy with concomitant intraoperative gastroscopy was performed. Pathological examination of the resected specimen showed a type Ⅱc-like lesion with a maximum diameter of 6 mm in the mucosal layer along with spindle cell proliferation. Immunostaining was negative for c- kit, DOG1, CD34, S-100, SMA, WT-1, desmin(N), EMA, and keratin(pan)and positive for β-catenin, Bcl-2, and vimentin; furthermore, low Ki-67(MIB-1)expression was detected. Therefore, GIST, solitary fibrous tumor, leiomyoma, leiomyosarcoma, desmoid tumor, spindle cell carcinoma, and synovial sarcoma were excluded, and an unclassifiable spindle cell tumor arising from the gastric mucosa was diagnosed. The patient has remained recurrence-free for 1 year and 8 months post-operatively and is currently under careful outpatient follow-up.

[Gastrointestinal mesenchymal tumors: a clinical pathologic and immunohistochemical study of 210 cases].

To study the clinical pathologic and immunohistochemical features of gastrointestinal mesenchymal tumors (GIMTs), and to investigate the value of molecular markers in GIMTs clinical differentiation diagnosis. The clinical and pathological data of 210 cases of GIMTs, collected from Jan. 1987 to Dec. 2005 in our hospital, were investigated retrospectively. GIMTs were rediagnosed by using standard immunostaining technique in paraffin-embedded tissue. The expression level of CD117, CD34, Desmin, SMA and PS100 were detected by immunohistochemical method. Among 210 cases of GIMTs, 127 cases were Gastrointestinal stromal tumors (GISTs) (60.5%), 33 leiomyomas and leiomyosarcomas (15.7%), 27 neurogenic tumours (12.8%), and 23 miscellaneous tumors (11.0%). The incidences of GIST, leiomyoma and leiomyosarcoma were similar among men and women. Men were more likely to develop neurogenic tumors and miscellaneous tumors than women. Of all the GISTs, 51.2% cases originated from stomach, 19.7% from small intestine, 11.0% from esophagus, 10.2% from colon and rectum. The most common location of leiomyomas and leiomyosarcomas was esophagus (45.5%). The most common location of neurogenic tumors was retroperitoneum (74.1%). Common symptoms of GISTs included digestive tract hemorrhage in 36 cases (28.3%), abdominal pain in 27 cases (21.3%) and abdominal mass in 24 cases (18.9%). Other GIMT cases except GISTs had no first symptom of digestive tract hemorrhage. It was noticed that 79.5% of GISTs had no obvious invasion, and 72.7% of leiomyomas and leiomyosarcomas had no obvious invasion. 33.3% of neurogenic tumors invaded the adjacent organs or tissues. No metastases had been found in other GIMT cases except GISTs. The neoplastic cells of GISTs were composed of various percentage of spindle (72.5%), epithelioid (11.8%) and mixed-type cells (15.7%). The percentage of spindle cells in leiomyomas and leiomyosarcomas was 94. The immunohistochemical results of GISTs showed that the positive rate of CD117 was 93.7%, CD34 was 69.3%, Desmin was 13.4%, SMA was 12.6%, and PS100 was 10.2%. The immunohistochemical results of leiomyomas and leiomyosarcomas showed that the positive rate of Desmin was 78.5%, SMA was 63.6%, while as the expressions of CD117, CD34, and PS100 were negative. Diffuse strong positive staining of PS100 was observed in 88.9% of neurogenic tumor patients. GISTs are the most common tumors among GIMTs. GISTs are different from neurogenic tumors, leiomyomas and leiomyosarcomas in initial symptom, tumor location, biological behavior and immunophenotype. Immunohistochemistry plays an important role in differentiating GISTs from leiomyomas and neurogenic tumors.

[Analysis of prognostic and clinicopathologic factors in gastrointestinal stromal tumors of the stomach].

To identify the clinical pathological characteristics and prognostic factors in patients with gastrointestinal stromal tumors of the stomach. The data of 98 patients of gastric stromal tumors, leiomyomas, leiomyosarcomas, leiomyoblastomas, schwannomas and neurofibromas, collected from Mar. 1983 to Dec. 2001 in our hospital with complete clinical and pathological data, were investigated retrospectively. Gastric stromal tumors were diagnosed by reviewing the tumor slides stained with hematoxylin and eosin (H&E). Two histomorphologically representative areas of each tumor slides were identified and arrayed on a tissue microarray. Immunohistochemistry staining were performed using antibodies to c-kit (CD117), CD34, smooth muscle actin (SMA), Desmin and S-100 proteins. The relations of various clinicopathologic characteristics and outcomes were tested by univariate analysis and multivariate analysis. Ninety-one patients were clearly identified as gastric stromal tumors from the 98 patients, who were diagnosed as gastric stromal tumor, leiomyoma, leiomyosarcoma, leiomyoblastoma schwannoma and neurofibroma (92.9%). The follow-up rate was 91% and the median follow up time was 54 months. The patient survival rates at 1, 5 and 10 years were 88.8%, 79.6% and 63.7% respectively. Univariate analysis showed that tumor size, mitotic count, tumor necrosis, nuclear pleomorphism, cell type, cell density, surgical procedure, mucosal invasion, age and lable index of Ki-67 were associated with prognosis (P<0.05). Multivariate analysis showed that tumor size, mitotic count, mucosal invasion and tumor necrosis were predictors of prognosis (P<0.05). Tumor size of >10 cm, mitotic count of >10 mitoses per 50 high power fields, necrosis and mucosal invasion are often associated with an aggressive clinical course in gastric stromal tumors.

[Clinicopathological, immunohistochemical and molecular genetic study of intra-abdomen extra-gastrointestinal stromal tumors].

To explore the clinicopathological, immunohistochemical and molecular genetic features of intra-abdomen extra-gastrointestinal stromal tumors (EGISTs) and their differential diagnosis. Nine cases of EGISTs from the abdominal cavity or retroperitoneum which were previously diagnosed as leiomyoma, leiomyoblastoma, or leiomyosarcoma etc. by a panel of antibodies such as CD117, CD34, alpha-SMA, MSA, desmin, S-100, and PGP9.5 from which five cases were detected for c-kit gene mutation. The tumors occurred in 5 men and 4 women, the age ranged from 38 to 72 years (mean 61.7 years). Four cases arose from the mesentery, two from omentum, two from retroperitoneum and one located at the hilus of the spleen. The size of tumors ranged from 5 cm to 23 cm (mean 12.9 cm) in diameter and the tumor cell components varied: mainly spindle cells (seven cases), epithelioid cells (one case), mixed cells (one case). Tumors expressed CD117 (8/9), CD34 (5/9), alpha-SMA (3/9), MSA (4/9), desmin (0), S-100 protein (1/9) and PGP9.5 (1/9). Of the five cases examined for heterozygous deletion mutation of 11 exon of the c-kit gene two were found positive. Two borderline cases showed long-term survival of 8 years and 11 years, respectively. In seven malignant cases, two showed adverse outcome, one survived 4 years without recurrence, two were lost in follow up and two new cases were still being in followed. GIST-type stromal tumors can also occur in the abdomen, most cases were borderline or malignant, tumor coagulative necrosis, mitoses >or= 5 per 50 high-power fields and obvious nuclear atypia indicating malignancy. Differential diagnosis of EGIST including benign or malignant smooth muscle tumors, benign or malignant nerve sheath tumors etc.

Gastroblastoma

Histology The tumour is biphasic and contains spindle and epithelial cells. The spindle cells form diffuse sheets. The epithelial cells occur in clusters which may form glandular structures. Immunochemistry The epithelial component is positive for keratin (keratin AE1/AE3, keratin 18, keratin 7) c-KIT and CD56. The mesenchymal component is positive for CD10 and vimentin. Electron microscopy Desmosomes and microvilli are present. Differential diagnosis The histological differential diagnosis includes Carcinosarcoma Biphasic synovial sarcoma Teratoma Mixed tumor Other rare stomach tumours Several other rare tumours that may need to be considered in the differential diagnosis include Multiple minute gastrointestinal stromal tumor Interstitial cell of Cajal hyperplasia Nerve sheath tumors (schwannoma and perineurioma) Granular cell tumor Glomus tumor Plexiform angiomyxoid myofibroblastic tumor Primary clear cell sarcoma History

Gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. GISTs arise in the smooth muscle pacemaker interstitial cell of Cajal, or similar cells. They are defined as tumors whose behavior is driven by mutations in the KIT gene (85%), PDGFRA gene (10%), or BRAF kinase (rare). 95% of GISTs stain positively for KIT (CD117). Most (66%) occur in the stomach and gastric GISTs have a lower malignant potential than tumors found elsewhere in the GI tract.

Stromal tumor

Gastrointestinal stromal tumors (GISTs) form in the soft mesenchymal tissue of the gastrointestinal tract and form from the rapid growth of interstitial cells of Cajal (ICCs). GISTs are the most common type of tumor found in the gastrointestinal tract, usually located in the small intestine or stomach. Approximately 10-20 million individuals are diagnosed with this type of tumor every year (Stamatakos et al., 2009). GISTs are most common in individuals ranging in age from 40 years old to 70 years old and are rare in small children and young adults. Individuals with these tumors may experience swelling in the abdomen, pain, vomiting, nausea, appetite loss, weight loss, low blood cell counts, gastrointestinal bleeding (which can result in bloody or dark stool), weakness, and tiredness. The prognosis for these types of tumors depends heavily on the size of the tumor and the rate of mitosis, however approximately 60% of GISTs are diagnosed as benign. Surgery to remove the tumor is the

Rectal GIST presenting as a submucosal calculus.

This case report presents an incidental finding of a rectal GIST (gastrointestinal stromal tumor) presenting as a submucosal calculus, not previously reported. A 53-year-old man without a significant medical history presented with abdominal pain in the left lower quadrant, and with constipation. Upon rectal examination, a hard submucosal swelling was palpated 4 cm from the anus, at 3 o'clock, in the left rectum wall. X-ray photos, computerized tomography (CT)-scan and a magnetic resonance imaging (MRI) scan clearly showed a calculus. Excision revealed a turnip-like lesion, 3.1 x 2.3 x 1.8 cm. Analysis showed it was a rectal GIST, a rare mesenchymal tumor of the gastrointestinal tract, which expressed CD117 (or c-kit, a marker of kit-receptor tyrosine kinase) and CD34. Calcification is not a usual clinicopathological feature of GISTs [1-3], and although a number of rectal GISTs have been reported [4-9], we have found no cases so far of rectal GIST presenting as a submucosal calculus. In general, GISTs are rare mesenchymal tumors of the gastrointestinal tract (nerve tissue, smooth muscle). Histology and immunohistochemistry discriminate gastrointestinal stromal tumors from leiomyomas and neurinomas. The most important location is the stomach; the rectal location is rare. Usually, the classic signs of malignancy such as cellular invasion and metastasis are missing. A set of histologic criteria stratifies GIST for risk of malignant behavior such as mitotic activity and tumor size, cellular pleomorphism, developmental stage of the cell and quantity of cytoplasma [7,13]. Tumors with a high mitotic activity and size above 5 cm are considered malignant. Recent pharmacological advances such as tyrosine kinase inhibitors have determined c-kit (i.e., CD117) as the most important marker, amongst others. C-kit positive tumors respond extremely well to chemotherapy with Imatinib (Glivec, Gleevec) [10-12].

Clinical manifestations and prognostic factors in patients with gastrointestinal stromal tumors.

To investigate the incidence of CD117-positive immunohistochemical staining in previously diagnosed gastrointestinal (GI) tract stromal tumors (GIST) and to analyze the tumors' clinical manifestations and prognostic factors. We retrospectively reviewed 91 cases with a previous diagnosis of GI stromal tumor, leiomyoma, or leiomyosarcoma. Tissue samples were assessed with CD117, CD34, SMA and S100 immunohistochemical staining. Clinical and pathological characteristics were analyzed for prognostic factors. CD117 was positive in 81 (89%) of 91 tissue samples. There were 59 cases (72.8%) positive for CD34, 13 (16%) positive for SMA, and 12 (14.8%) positive for S100. There was no gender difference in patients with CD117-positive GIST. Their mean age was 65 years. There were 44 (54%) tumors located in the stomach and 29 (36%) in the small intestine. The most frequent presenting symptoms were abdominal pain and GI bleeding. The mean tumor size was 7.5 +/- 5.7 cm. There were 35 cases (43.2%) with tumors >5 cm. The tumor size correlated significantly with tumor mitotic count and resectability. Tumor size, mitotic count, and resectability correlated significantly with tumor recurrence and survival. There was recurrent disease in 39% of our patients, and their mean survival after recurrence was 16.6 months. Most recurrences were at the primary site or metastatic to the liver. Twenty-six percent of our patients died of their disease. Traditional histologic criteria are not specific enough to diagnose GIST. This diagnosis must be confirmed with CD117 immunohistochemical staining. Prognosis is dependent on tumor size, mitotic count, and resectability.

Gastric schwannoma.

Gastrointestinal mesenchymal tumors are a group of tumors originated from the mesenchymal stem cells of the gastrointestinal tract, consisting of gastrointestinal stromal tumors (GIST), leiomyomas or leiomyosarcomas or schwannomas. Gastric schwannoma is a very rare gastrointestinal mesenchymal tumor, which represents only 0.2% of all gastric tumors and 4% of all benign gastric neoplasms. We report a 24-year-old girl who suffered from an episode of upper gastrointestinal bleeding. The endoscopic examination showed a round submucosal tumor with a central ulceration and bleeding over the high body of the stomach. Surgical resection of the tumor was performed. The pathological examination revealed a picture of spindle cell tumor that was strongly positive for S-100 protein stain, and non-reactive for CD34, CD117, actin, HHF-35, desmin, melan-A and HMB-45, consistent with gastric schwannoma. The literature is reviewed.

[Clinical analysis of 31 patients with gastric stromal tumors].

To investigate the clinical manifestations, diagnosis and treatment of gastric stromal tumors. 31 patients with gastric stromal tumors treated from 1993, 1 - 2001, 9 were analyzed retrospectively. All cases were diagnosed by pathological and immunohistochemistry examinations. According to Levin's standard combining with Hurliman's and Goldbum's methods, the patients were classified. There are no significant difference between male and female patients. 50 - 60 years old patients have high incidence. The distribution of gastric tromal tumors is fundus > body > antrum. Diagnosis of this condition is sometimes difficult and treatment is often delayed because patients usually present with nonspecific abdominal symptoms. The main manifestations of gastric stromal tumors are upper gastrointestinal hemorrhage 61.3% (19/31), 7 patients with acute hemorrhage and 12 with chronic hemorrhage. Most of them were malignant. Abdominal malaises and/or distention 32.3% (10/31) and abdominal pain 22.6% (7/31). Gastroscopy, ultrasound gastroscopy, computed tomography, B type ultrasound and upper gastrointestinal X-ray series are helpful to diagnosis. But the final diagnosis is decided by pathological and immunohistochemistry examinations. Gastric stromal tumors exhibit consistent immunohistochemical expressions of CD(117) and/or CD(34). The operative treatment is thought of the first choice. Effect of the chemotherapy isn't satisfied. There is no standard chemotherapy for gastric stromal tumors. Gastric stromal tumor is a kind of separated submucosal tumor which is different from leiomyoma, leiomyosarcoma and neurogenic tumors. Pathological and immunohistochemistry inspectations are very important to make clear diagnosis. Early diagnosis and rational treatment are the keys to improve the prognosis.

Carney's triad

In addition to these three classical tumors, there is an increased incidence of pheochromocytoma, esophageal leiomyoma and adrenocortical adenoma. The original description employed the then-prevailing terminology of gastric epithelioid leiomyosarcoma. Subsequent advances in molecular biology have led to the current terminology of gastrointestinal stromal tumors (GISTs). However, there is limited evidence to suggest that the gastrointestinal stromal tumors (GIST) in Carney triad lack CD117 (c-kit) mutations (i.e., they are wild-type), and hence these GISTs may prove unresponsive to Imatinib. Taxonomy Carney triad is distinct from two other multiple neoplasia syndromes, also described by J. Aiden Carney. Carney complex The Carney complex is a distinct entity, characterized by myxomatous neoplasms (cardiac, endocrine, cutaneous and neural), and a host of pigmented lesions of the skin and mucosae, including the rarely occurring epitheloid blue nevus.

Extragastrointestinal Stromal Tumor (EGIST) in the abdominal wall: Case report and literature review.

Gastro Intestinal Stromal Tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract (GI). GIST that arises primarily outside the GI tract is termed Extragastrointestinal Stromal Tumor (EGIST). To the best of our knowledge, few cases of EGIST in the abdominal wall were reported. We present a rare case of EGIST in the abdominal wall of a 57 year-old female patient. The asymptomatic tumor was located in the superior aspect of the left rectus abdominis muscle, measured 5.4 × cm 5.3 × cm 6.9 cm and was well circumscribed. Histological examination showed an epithelioid cell morphology. The mitotic count was 7/50 HPFs. Immunohistochemistry showed diffuse strong CD117 positivity, focal positivity for S100. The tumor was excised and the margins were free of malignancy. The patient was doing well postoperatively and was discharged on STI-571 regimen. Although GIST is the most common mesenchymal tumor of the gastrointestinal tract, a case with EGIST in the abdominal wall is rare. Positive immunohistochemical staining for CD117 is a defining feature of GISTs. A great percentage of EGISTs represent a metastasis from a primary GIST. In our case, the clinical and diagnostic work-up have been proved it to be an EGIST. The existing data on EGIST is insufficient to make a final conclusion regarding the malignant potential and clinicopathological factors of EGISTs that determine patient prognosis. Thus a follow-up for a long period is required. EGISTs should be kept in mind in the differential diagnosis for patients presenting with solid mass of the abdominal wall.

Immunohistochemical spectrum of GISTs at different sites and their differential diagnosis with a reference to CD117 (KIT).

Gastrointestinal (GI) stromal tumor (GIST) is the designation for the major subset of GI mesenchymal tumors and encompasses most tumors previously classified as GI smooth muscle tumors. Although GISTs typically express CD117 (KIT), often express CD34, and sometimes express alpha-smooth muscle actin (SMA), the relative frequency of these markers has not been characterized in large series of GISTs of different sites, and the CD117 expression has not been fully characterized in intra-abdominal tumors. In this study, we immunohistochemically analyzed 292 GISTs throughout the GI tract, including omentum and mesentery, and compared the immunoreactivities with 211 other tumors that may enter in the differential diagnosis. GISTs were defined in this study as CD117-positive primary spindied or epithelioid mesenchymal tumors of the GI tract, omentum, or mesentery. The CD34 positivity of GISTs varied from 47% in small bowel to 96 to 100% in rectum and esophagus, whereas SMA expression showed the opposite patterns and was most frequent in the GISTs of small bowel (47%) and rarest in the GISTs of rectum and esophagus (10-13%). Desmin was seen only occasionally. S100 positivity was rare but was seen most frequently in small intestinal GISTs (15%). True leiomyomas from esophagus, muscularis mucosae of colorectum, and pericolic leiomyomas similar to uterine leiomyomas were negative for CD117 and CD34 and positive for SMA and desmin (46 of 46). Inflammatory fibroid polyps of stomach and small intestine were negative for CD117 but were often positive for CD34 (6 of 8) and variable for SMA (3 of 8). Inflammatory myofibroblastic tumors involving gastric or colonic wall were negative for CD117 but some showed CD117-positive endothelia. GI schwannomas were all negative for CD117 and positive for S100 protein (11 of 11). Extremely focal CD117 positivity was seen in the neoplastic cells of some retroperitoneal leiomyosarcomas and liposarcomas. Among other CD117-positive tumors were intestinal metastatic melanomas (8 of 11) and extraskeletal Ewing's sarcomas (5 of 11), two of which were abdominal. In conclusion, strong CD117 expression defines most primary GI mesenchymal tumors as GISTs, which show different patterns for CD34 and SMA in various parts of the GI tract. Some unrelated CD117-positive tumors (melanomas, Ewing's sarcomas) should not be confused with GISTs.

Gastrointestinal stromal tumors/smooth muscle tumors (GISTs) primary in the omentum and mesentery: clinicopathologic and immunohistochemical study of 26 cases.

Gastrointestinal stromal tumor or smooth muscle tumor (GIST) is the designation for a major subset of gastrointestinal mesenchymal tumors that histologically, immunohistochemically, and genetically differ from typical leiomyomas, leiomyosarcomas, and schwannomas. Because GISTs, like the interstitial cells of Cajal, the gastrointestinal pacemaker cells, express CD117 (c-kit protein), the origin of GISTs from the interstitial cells of Cajal has been recently proposed. Comparison of GISTs primary in the omentum and mesentery to GISTs primary in the tubular gastrointestinal tract is of particular diagnostic and histogenetic interest in view of the possible similarity of these tumors with the GIST group. In this study, we analyzed 14 omental and 12 mesenteric primary mesenchymal tumors representing smooth muscle tumors or GISTs. These tumors were phenotypically compared with gastric and small intestinal GISTs, leiomyomas of the esophagus, and leiomyosarcomas of the retroperitoneum. Most (13 of 14) omental and mesenteric (10 of 12) tumors showed histologic features similar to GISTs with elongated spindle cells or epithelioid cells with high cellularity; most of these tumors showed low mitotic activity. Omental and mesenteric GISTs were typically positive for CD117 and less consistently for CD34. They often showed alpha-smooth muscle actin reactivity but were virtually negative for desmin and S-100 protein. One omental and two mesenteric tumors showed features of leiomyosarcoma with ovoid, less elongated nuclei, cytoplasmic eosinophilia; all these tumors had significant mitotic activity. These tumors were positive for alpha-smooth muscle actin and two of them for desmin, but all were negative for CD34 and CD117, similar to retroperitoneal leiomyosarcomas. Tumor-related mortality occurred in the group of mesenteric GISTs, but not in the group of omental GISTs. In contrast, all three patients with a true leiomyosarcoma of the omentum or mesentery had documented liver metastases or died of tumor. In summary, we show that tumors phenotypically identical with GISTs occur as primary tumors in the omentum and mesentery. The occurrence of CD117-positive tumors outside the gastrointestinal tract militates against an origin of these tumors exclusively from the interstitial cells of Cajal.

Hemoperitoneum caused by a ruptured GIST located in the posterior gastric wall managed by endoscopic diagnosis and laparoscopic treatment: case report and literature review.

A case of hemoperitoneum caused by a ruptured gastrointestinal stromal tumor (GIST) of the posterior gastric wall is presented. An otherwise healthy 81-year-old man presented with abdominal pain/tenderness and anemia (hemoglobin: 7.4 g/dL). Computed tomography scan showed hemoperitoneum and a gastric mass of uncertain nature. As the patient was hemodynamically stable, a mini-invasive approach was decided. Esophagogastroscopy revealed an umbilicated mass of the posterior gastric wall, therefore allowing for a correct preoperative diagnosis of GIST and its appropriate treatment by laparoscopic atypical gastrectomy. Laparoscopically, a longitudinal resection of gastric fundus including the tumor was performed in a sleeve gastrectomy fashion, 25 minutes after the induction of pneumoperitoneum. The outcome was uneventful. Pathologic examination confirmed a benign 4 × 3-cm gastric GIST with <1 mitosis per 50 high power field, staining positive for CD117 (C-KIT) and negative for S-100 protein and smooth muscle actin. To our knowledge, it is the first case of a successful laparoscopic resection of an endoscopically diagnosed gastric GIST in an emergency setting. Hemoperitoneum is a rare, potentially severe complication of GIST. As bleeding is rarely severe, most patients may benefit from a mini-invasive approach, even if the tumor is located in the posterior gastric wall.

[Gastrointestinal stromal tumours and acute haemorrhage: description of four cases].

Gastrointestinal stromal tumours are uncommon neoplasias arising from stromal tissue of the intestinal wall. Discovery of the protooncogene c-kit and the presence of the CD117 protein on the neoplastic cells of the majority of gastrointestinal stromal tumours may suggest their possible origin from Cajal cells. The clinical symptoms of gastrointestinal stromal tumours are related to tumour size and are generally aspecific: acute or chronic bleeding, abdominal pain and palpable mass are some of the most common signs. Digestive endoscopy or US-endoscopy for gastroduodenal tumours, ultrasonography and CT scans are the procedures of choice in the evaluation of the location, size, invasion of adjacent organs and metastases. Surgery is the only curative therapy for gastrointestinal stromal tumours. Chemotherapy or radiotherapy are of no use for metastatic disease, but good results are obtained with ST1571 in advanced disease. In the absence of metastases, it is quite difficult to distinguish between benign and malignant lesions. The most important prognostic factors are number of mitoses and tumour size. We report here on 4 consecutive cases of gastrointestinal tumours, 2 gastric and 2 duodenal, which presented with acute gastrointestinal bleeding.

Giant gastrointestinal stromal tumor of the stomach.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal malignancies of the digestive tract. Gastric localization is the most frequent. The aim of this study is to evaluate the importance of immunohistochemical factors (CD117, CD34, α-SMA, vimentin, p53, Ki67) in diagnostic and size tumor and mitotic activity as prognostic factors for these tumors. We present the case of a 66-year-old male patient with a giant gastric GIST. Like in the vast majority, the symptomatology in this patient has long been faint, despite the large tumor size, and when it became manifest, it was nonspecific. Imagery wise, the computer tomography (CT) scan was the most efficient, showing the origin of the tumor from the greater curvature of the stomach, its dimensions, as well as the relations with the other abdominal viscera. Surgery in this patient was en-bloc, according to the principles of GIST. The histological aspect is characterized by a proliferation of spindle cells positive for CD117 and CD34. Despite complete microscopic resection, the size of the tumor (25×20×27 cm) and the mitotic activity (21÷5 mm2) remains important relapse factor.

Gastrointestinal stromal tumor

Due to the change in definition, clinical pathways of care before the year 2000 are largely uninformative in the current era. Signs and symptoms GISTs may present with trouble swallowing, gastrointestinal bleeding, or metastases (mainly in the liver). Intestinal obstruction is rare, due to the tumor's outward pattern of growth. Often, there is a history of vague abdominal pain or discomfort, and the tumor has become rather large by time the diagnosis is made.

Meckel's diverticulum

Umbilical anomalies Anomalies between the diverticulum and umbilicus may include the presence of fibrous cord, cyst, fistula, or sinus, leading to: Infection or excoriation of periumbilical skin, resulting in a discharging sinus Recurrent infection and healing of sinus Abscess formation in the abdominal wall Fibrous cord increases the risk of volvulus formation and internal herniation Neoplasm Tumors in Meckel's diverticulum may cause bleeding, acute abdominal pain, gastrointestinal obstruction, perforation or intussusception. Benign tumors: Leiomyoma Lipoma Vascular and neuromuscular hamartoma Malignant tumors: Carcinoids: most common, 44% Mesenchymal tumors: Leiomyosarcoma, peripheral nerve sheath and gastrointestinal stromal tumors, 35% Adenocarcinoma, 16% Desmoplastic small round cell tumor

Extragastrointestinal stromal tumour of the abdominal wall - a case report.

Stromal tumours occurring in areas other than the GastroIntestinal Tract (GIT) are known as Extra GastroIntestinal Stromal Tumours (EGISTs). They usually arise in the mesentery, omentum or retroperitoneum, while EGISTs which occur in the abdominal wall are very rare. Both gastrointestinal stromal tumours (GISTs) and EGISTs are histologically and immunophenotypically similar. We are reporting a case of EGIST, which occurred in the anterior abdominal wall in a twenty five-year-old female patient. The tumour was present in the right loin and imaging studies suggested that it was a desmoid tumour. It was surgically excised by doing an abdominal wall mesh repair. The histological examinations revealed a tumour with spindle cell morphology, with <2 mitoses per 50 High Power Field (HPF) and no necrosis, with tumour free margins. Immunohistochemistry was strongly positive for CD117 and Smooth Muscle Actin (SMA), while it was negative for β-catenin and S100. The patient is well post operatively and is on close follow up. EGISTs should be considered in the differential diagnosis of mesenchymal tumours which occur in the abdominal wall, inspite of their rarity, as the high risk patients may need Imatinib chemotherapy.

Uterine sarcoma

The uterine sarcomas form a group of malignant tumors that arises from the smooth muscle or connective tissue of the uterus. Signs and symptoms Clinically, uterine sarcomas and leiomyomas (fibroids) both have similar symptoms such as increased uterine size, abdominal pain and vaginal bleeding so it can be difficult to tell them apart.Unusual or postmenopausal bleeding may be a sign of uterine sarcoma and needs to be investigated. Other signs include pelvic pain, pressure, and unusual discharge. A nonpregnant uterus that enlarges quickly is suspicious. However, none of the signs are specific. Specific screening test have not been developed; a Pap smear is a screening test for cervical cancer and not designed to detect uterine sarcoma. Histology Tumoral entities include leiomyosarcomas, endometrial stromal sarcomas, carcinosarcomas and "other" sarcomas.

Hemorrhagic polypoid gastric and colonic metastases nine years after uterine leiomyosarcoma - case report.

Uterine leiomyosarcoma (ULMS) is a rare tumor, representing 1-2% of all uterine malignancies. It is highly aggressive, with high metastatic rate, especially in lungs, peritoneal cavity, retroperitoneum, bones and liver, usually during the first years after diagnosis. A 58-year-old woman, with subtotal hysterectomy and bilateral adnexectomy, followed by radiochemotherapy for spindle-type ULMS nine years ago, presented with gastrointestinal bleeding and severe anemia. Three polyps ranging from 2 cm to 5 cm in diameter were found at gastroscopy, the largest being ulcerated, which required a total gastrectomy three months later. Colonoscopy identified two pedunculated polyps on the descending colon, 2 cm and 3.5 cm in diameter. Histologically, both sites revealed proliferations of spindle cells with whorled pattern, moderate to severe nuclear atypia, 5 to 8 mitotic figures (MFs)÷10 high-power fields (HPFs) and additional necrosis in the gastric tumors. Immunohistochemistry was negative for CD117, DOG1, S100 and CD34 and positive for smooth muscle actin (SMA), estrogen receptor (ER) and progesterone receptor (PR). Twenty percent of nuclei stained positive for Ki67. The diagnosis was synchronous hemorrhagic gastric and colonic polypoid metastases of ULMS. Thoracic computed tomography (CT) and abdominal ultrasonography were negative for other metastatic lesions, while abdominal CT revealed abdominal and pelvic lymphadenopathy. This case illustrates a distinct pattern of metastasis that is an extremely rare gastric and colonic location and an expanded disease-free period of nine years since the initial treatment. A long-term clinical and imaging follow-up of this patient is essential.

Sarcoma

Signs and symptoms Symptoms of bone sarcomas typically include bone pain, especially at night, and swelling around the site of the tumor. Symptoms of soft-tissue sarcomas vary, but they often present as firm, painless lumps or nodules. Gastrointestinal stromal tumors (a subtype of soft tissue sarcoma) often are asymptomatic, but can be associated with vague complaints of abdominal pain, a feeling of fullness, or other signs of intestinal obstruction. Cause

Krukenberg tumor

A Krukenberg tumor refers to a malignancy in the ovary that metastasized from a primary site, classically the gastrointestinal tract, although it can arise in other tissues such as the breast. Gastric adenocarcinoma, especially at the pylorus, is the most common source. Krukenberg tumors are often (over 80%) found in both ovaries, consistent with its metastatic nature. Signs and symptoms Krukenberg tumors often come to the attention when they cause abdominal or pelvic pain, bloating, ascites, or pain during sexual intercourse. Krukenberg tumors can occasionally provoke a reaction of the ovarian stroma which leads to hormone production, that results in vaginal bleeding, a change in menstrual habits, or hirsutism, or occasionally virilization as a main symptom. In rare cases the disease can manifest with hydronephrosis and hydroureter.

Exophytic pedunculated gastrointestinal stromal tumor with remarkable cystic change.

A 59-year-old man with bloody stools, and previously diagnosed with sigmoid colon carcinoma, visited our hospital. Preoperative abdominal ultrasonography (US) showed another tumor, with an uneven irregular surface, measuring about 9 x 5 cm, below the left hypochondrium. The tumor consisted of several cysts. Abdominal computed tomography (CT) showed a multicystic tumor attached to the stomach, and its septum and marginal region were intensely stained on contrast imaging. On magnetic resonance imaging (MRI), low and markedly high signals were revealed in the tumor on T1-weighted and T2-weighted sequences, respectively. Contrast imaging of the upper digestive tract showed extramural compression of the greater curvature of the antral stomach by the tumor. The tumor was partially imaged by endoscopic ultrasonography (EUS), but continuity to the stomach was not confirmed. On abdominal angiography, the tumor was slightly stained via the gastroepiploic arteries. Surgical treatment was performed to excise both the gastric tumor and the sigmoid colon carcinoma. The gastric tumor was removed with gastric wall tissue where the tumor was attached to a 2-cm pedicle. It was multicystic, contained watery fluid, and had a smooth outer surface. Histologically, the tumor consisted of multiple irregular cysts without epithelial lining, and solid epitheloid cell nests in between. The tumor cells had clear or eosinophilic cytoplasm and round nuclei. No mitotic figures were seen. The tumor cells in the pedicle were connected with the muscularis propriae of the stomach. Immunohistochemistry showed c-kit-positive, CD34-positive smooth muscle actin (SMA)-negative, and S-100-negative staining of tumor cells. The final diagnosis was gastrointestinal stromal tumor (GIST).

Gastric Angiomyolipoma, a Very Rare Cause of Upper Gastrointestinal Bleeding: A Case Report and a Brief Review of Literature.

Angiomyolipoma (AML) is a tumor composed of variable proportions of adipose tissue, spindle and epithelioid smooth muscle-like cells and abnormal thick-walled blood vessels which are usually benign. AML is relatively common in kidney and liver. Gastric angiomyolipoma (GAML) is extremely rare and only 2 cases were reported in the literature. Diagnosis of AML is difficult owing to its rarity and varied immunohistochemical patterns. Here, we report a case of GAML in a 65-year-old male who presented with an episode of hematemesis and intermittent melena for one week. Endoscopy showed a partially obstructing mass arising from gastric antrum with central ulceration. Mass was removed by wedge resection after laparoscopic anterior gastrectomy. Excised specimen showed a benign 6 × 3 × 3 cm homogenous fatty mass with adipose tissue, smooth muscles and prominent vascularity. Immunohistochemistry stains were positive for desmin, smooth muscle actin (SMA), CD34 and negative for human melanoma black (HMB)-45 antigen and CD117. This case reports the largest and HMB-45 negative GAML so far, which can be a very rare cause of upper gastrointestinal bleeding.

Gastrointestinal stromal tumor

When GIST is suspected—as opposed to other causes for similar tumors—the pathologist can use immunohistochemistry (specific antibodies that stain the molecule CD117 [also known as c-kit] —see below). 95% of all GISTs are CD117-positive (other possible markers include CD34, DOG-1, desmin, and vimentin). Other cells that show CD117 positivity are mast cells. If the CD117 stain is negative and suspicion remains that the tumor is a GIST, the newer antibody DOG-1 (Discovered On GIST-1) can be used. Also sequencing of Kit and PDGFRA can be used to prove the diagnosis.

Primary gastric angiosarcoma presenting as an asymptomatic gastric submucosal tumor.

Primary gastric angiosarcoma is a rare gastric tumor. Previously reported cases are limited and usually symptomatic. Preoperative diagnosis is difficult and should be differentiated from adenocarcinoma or gastrointestinal stromal tumor. We report a 55-year-old man with primary gastric angiosarcoma presenting as an asymptomatic gastric submucosal tumor. Abdominal ultrasonography showed a heteroechogenic tumor with several notably anechoic portions between the stomach and the gallbladder. Computed tomography showed that the tumor originated from the stomach, and upper gastrointestinal endoscopy showed a large gastric submucosal tumor at the lower body. Laparotomy was performed and a purple circumscribed tumor measuring 8.5 x 5.0 x 4.0 cm was found on the serosal aspect of the lower body. The tumor was soft and spongy with areas of hemorrhagic pools on section. Microscopically, the tumor was composed of proliferative neoplastic spindle to epithelioid cells. The neoplastic cells infiltrated and dissected the smooth muscle as vessel-forming architectures. On immunohistochemical study, the tumor cells were positive for CD34. These findings confirmed a diagnosis of primary gastric angiosarcoma. The patient has been well during the 11-month postoperative follow-up.

International Classification of Diseases for Oncology

M8920/3 Alveolar rhabdomyosarcoma M8921/3 Rhabdomyosarcoma with ganglionic differentiation Ectomesenchymoma 893–899 Complex Mixed And Stromal Neoplasms M8930/0 Endometrial stromal nodule M8930/3 Endometrial stromal sarcoma, NOS Endometrial sarcoma, NOS Endometrial stromal sarcoma, high grade M8931/3 Endometrial stromal sarcoma, low grade Endolymphatic stromal myosis Endometrial stromatosis Stromal endometriosis Stromal myosis, NOS M8932/0 Adenomyoma Atypical polypoid adenomyoma M8933/3 Adenosarcoma M8934/3 Carcinofibroma M8935/0 Stromal tumor, benign M9835/1 Stromal tumor, NOS M8935/3 Stromal sarcoma, NOS M8936/0 Gastrointestinal stromal tumor, benign GIST, benign M8936/1 Gastrointestinal stromal tumor, NOS GIST, NOS/uncertain malignant potential Gastrointestinal autonomic nerve tumor (GANT) Gastrointestinal pacemaker cell tumor M8936/3 Gastrointestinal stromal sarcoma GIST, malignant