solitary true pancreatic cysts ( stpcs ) , or epithelial cysts , are benign lesions that are extremely rare in adult patients . advances in radiographic techniques have improved the ability to identify pancreatic cystic lesions .
we report a case of a large and symptomatic stpc in a 47-year - old female patient who was treated successfully with spleen - preserving laparoscopic distal pancreatectomy .
we also review the clinical and pathologic features of all reported stpcs within the past 25 years .
to compose the review , we did a search of the international literature for stpcs that had occurred in adults .
clinical and pathologic information was collected for all of the reported pancreatic cysts , and a database was formed .
the mean age of occurrence is 43.2 years , and the mean cyst size is 5.6 cm
cystic lesions of the pancreas are relatively rare , although they are considered an increasingly important category with a challenging differential diagnosis .
cystic lesions of the pancreas are commonly classified as pseudocysts , parasitic cysts , neoplastic cysts , and various types of congenital or acquired developmental benign cystic lesions such as retention cysts , duplication cysts , epithelial or true cysts , and lymphoepithelial cysts . based on the estimated relative frequency of pancreatic cystic lesions , pseudocysts are the most common .
they are caused by alcoholic , biliary , or traumatic acute pancreatitis and are nonepithelialized and non - neoplastic cysts .
neoplastic cystic lesions are represented by cysts with true lining ( mucinous and serous neoplasms ) and cysts with degenerative / necrotic change in a neoplasm ( solid pseudopapillary neoplasm , cystic ductal adenocarcinoma ) .
solitary true pancreatic cyst ( stpc ) is described as a simple thin - walled cyst with cuboidal lining and clear fluid content , whereas a lympoepithelial cyst is a uni- or multilocular cyst with well - differentiated squamous lining surrounded by a band of dense lymphoid tissue composed of mature t - lymphocytes with intervening germinal centers formed by b cells
. only a few cases of stpcs in adult patients are reported in the international literature .
the aim of this study is to report a new case of stpc in an adult patient .
we also review the literature on stpcs to determine the clinical features , management , pathological features , and prognosis of these lesions .
a 47-year - old woman was referred to our department with a history of discomfort and pain in her upper abdomen .
upper abdominal ultrasonography ( us ) revealed the presence of a 5.0-cm cystic lesion located in the tail of the pancreas .
abdominal computed tomography ( ct ) and magnetic resonance imaging ( mri ) scans were subsequently performed and confirmed the presence of a low - attenuation and well - demarcated cystic area , 4.5  3.5 cm in diameter , located in the tail of the pancreas ( figure 1 ) .
( b - d ) mri images displaying a unilocular , homogeneous , low - attenuated and well - demarcated cystic mass .
although the imaging features of the lesion appeared to be benign , surgical excision was done to rule out the probability of malignancy .
the cystic mass was excised en bloc with the tail of the pancreas , and the spleen was preserved ( figure 2 ) .
macroscopically viewed , the lesion was 6.6 cm in major diameter , with a fibrotic wall and an inner nodular appearance ( figure 3 ) .
a sample was taken for cytological and biochemical examinations and the results showed normal levels of amylase , ca 199 , and cea .
histopathologic studies showed that the cyst had a fibrotic wall and fibrosis in the inner surface foci of the cuboidal epithelium surface ( figure 4a ) .
immunochemical staining results showed the epithelial surface of the cyst was positive for cea and cam 5.2 ( figure 4b ) .
( a ) inner surface foci of the cuboidal epithelium ( hematoxylin and eosin stain , original magnification 100 ) .
( b ) positive stain for cam 5.2 ( original magnification 400 ) . based on histopathologic and immunohistochemical findings , the diagnosis of an stpc was made . at the postoperative course
, a small peripancreatic collection was detected 4 days after surgery and was conservatively treated .
postoperative imaging ( us and ct ) showed normal blood flow in the splenic vessels .
stpcs are typically diagnosed in childhood , predominantly in infants , and can be found in association with von hippel - lindau syndrome or polycystic disease of the kidneys .
the occurrence of stpcs in adults is extremely rare . to date , only a few cases of stpcs in adults have been described . 
 table 1 shows in detail all of the reported stpcs within the past 25 years . each article was carefully studied and a database was created that included the following stpc characteristics : gender , age , signs and symptoms , laboratory findings , diagnostic imaging modalities , localization , size , time of diagnosis , treatment , histopathology , fluid examination , and follow - up .
it is believed that true cysts derive from abnormal segmentation of the primitive pancreatic ducts , with resultant sequestered endothelial cells .
well - documented solitary true pancreatic cysts f = female ; m = male ; n / r = not recorded ; alp = alkaline phosphatase ; us = ultrasound ; ct = computed tomography ; mri = magnetic resonance imaging ; ercp= endoscopic retrograde cholangiopancreatography ; dp = distal pancreatectomy ; pd = pancreatoduodenectomy ; spldp = spleen - preserving laparoscopic distal pancreatectomy ; stpc = solitary true pancreatic cyst .
solitary true pancreatic cysts ' features in the articles we studied , stpcs were found in 14 female and 4 male patients ( f / m , 3.5:1 ) .
the mean diameter of the cysts was 5.6 cm , with range from 0.5 to 15.0 cm .
stpcs cause symptoms related to their size and location that include epigastric pain , nausea , vomiting , and biliary obstruction .
pain is described within the epigastrium and the back . a significant proportion ( 22.8% ) of the stpcs were detected incidentally and diagnosed during imaging for an unrelated medical problem .
the widespread use of abdominal imaging ( us , ct , and mri ) and the advances in quality of these technologies have increased the identification of asymptomatic pancreatic cysts . typically , small ( < 2 cm ) , serous , cystic lesions of the pancreas are benign .
larger ( > 2 cm ) , mucinous , multilocular cysts , or cysts with a solid component , carry the risk of malignancy .
however , these diagnostic modalities usually fail to differentiate preoperatively among the histologic variants of pancreatic cystic lesions .
with increasing use , endoscopic us plus fine - needle aspiration ( eus  fna ) is currently becoming an indispensable tool in the diagnosis of cystic lesions of the pancreas .
this combination provides more detailed anatomic information about the cyst than conventional us and allows the sampling of both cystic fluid and any solid component in smaller lesions .
nevertheless , in only one case of reported stpcs was an fna preoperatively performed , with uncertain results .
the inability to accurately diagnose the pathologic lesions gives rise to a controversy in the management of these patients .
management of asymptomatic incidental pancreatic cysts of 2 cm includes a follow - up initially at 6 months and then yearly by performing an imaging test at intervals , whereas fluid analysis is unnecessary .
incidental cysts may enlarge over time , and an increase to 2.5 cm and/or a change in morphology is an indication for surgery . the size criterion for resecting an enlarging incidental cyst without a change in morphology , however , is uncertain because cysts of 3 to 4 cm usually have a low potential for malignancy .
surgical intervention is considered the appropriate treatment for pancreatic cysts when symptoms are presented or if the cystic mass enlarges and compresses adjacent organs . in these cases , the risk of malignancy is high and surgery is considered mandatory .
other factors that advocate for surgery are asymptomatic large lesions , a location in the tail of pancreas , and age ( young patients 1735 years ) .
surgery includes cyst enucleation , cystoduodenostomy , cystogastrostomy , cystojejunostomy , and various types of pancreatectomies .
cyst enucleation is a safe and effective procedure for small lesions , especially if they are located in the pancreatic head .
benign and premalignant pancreatic body and tail cystic lesions can be treated with laparoscopic distal pancreatectomy ( ldp ) .
however , it is suggested the spleen be preserved if feasible , especially in young patients , because splenectomy can lead to life - threatening complications such as overwhelming postsplenectomy infection syndrome .
there are two distinct approaches to perform a spleen - preserving laparoscopic distal pancreatectomy ( spldp ) .
the classic procedure is to identify , isolate , and preserve the splenic artery and vein . alternatively
, the splenic artery and vein are ligated with the pancreas , and perfusion of the spleen is maintained by the short gastric vessels .
as with all pancreatic operations , wound infection , organ space infection , postpancreatectomy hemorrhage , and pancreatic fistula are all possible after ldp . he preoperative patency of the splenic vessels should be evaluated carefully , especially when spldp is attempted .
patients with poor vascular patency of the splenic vein had more postoperative pancreatic fistulas than did patients with normal vascular patency .
even after spldp , not all spleens can be salvaged because of postoperative hypoperfusion of the spleen , which may result in infarction and infection . after excision ,
the finding of a cuboidal epithelium layer is the key point in the diagnosis of an stpc .
stpcs usually contain clear fluid with normal amylase and lipase concentrations . in 83.3% of the reviewed cases ,
when it was performed , fluid analysis of stpcs showed normal amylase and lipase levels .
cyst fluid analysis may be helpful , but it is not always a sensitive and specific enough test .
immunostains included positive results for ca 199 , cea , ca 125 , and spain 1 .
these are not specific , however , because they are also positive stain findings in neoplastic cysts , pseudocysts , and lymphoepithelial cysts .
however , pseudocysts ' lack of endothelial lining and lymphoepithelial cysts ' lining is surrounded by a band of dense lymphoid tissue . to date , no case of malignancy has been reported in stpcs .
stpcs are extremely rare , benign pathologic entities , but the finding of a symptomatic or nonpancreatic cyst is still a diagnostic dilemma . imaging , endoscopic techniques , and tumor marker assays may partially resolve the problem , but a final diagnosis is still made only by histopathologic examinations of the specimen after surgery .
 background : solitary true pancreatic cysts ( stpcs ) , or epithelial cysts , are benign lesions that are extremely rare in adult patients . 
 advances in radiographic techniques have improved the ability to identify pancreatic cystic lesions . 
 we report a case of a large and symptomatic stpc in a 47-year - old female patient who was treated successfully with spleen - preserving laparoscopic distal pancreatectomy . 
 we also review the clinical and pathologic features of all reported stpcs within the past 25 years.database:to compose the review , we did a search of the international literature for stpcs that had occurred in adults . 
 fourteen related articles were found describing cases of stpcs . 
 clinical and pathologic information was collected for all of the reported pancreatic cysts , and a database was formed . 
 stpcs are detected more frequently in women than in men . 
 the mean age of occurrence is 43.2 years , and the mean cyst size is 5.6 cm 
 . fifty percent of true cysts are located in the head of the pancreas . 
 size and site are responsible for the symptoms caused , although 22.8% were asymptomatic . 
 diagnosis was made postoperatively in all cases by histopathologic studies . 
 no case of malignancy was reported in any stpc.conclusions:stpcs are rare and benign lesions commonly discovered incidentally during abdominal imaging . 
 surgical treatment is considered the appropriate therapy for large and symptomatic stpcs . 
 the definitive diagnosis is established by histopathologic and immunohistochemical studies . 