acinar cell carcinoma , also known as acinic cell carcinoma , is a malignant epithelial neoplasm composed of cells with morphological resemblance to acinar cells and with evidence of exocrine enzyme production by the neoplastic cells .
these carcinomas of the pancreas are rarely diagnosed pre - operatively , and surgical resection is the best treatment modality .
median overall survival after successful resection is 36 months in reported studies . a brief review of clinical presentation , diagnosis and management is discussed .
a 35-year old male patient presented in out patient department , with complaints of diarrhea for last 2 years and pain upper abdomen for last 15 days .
there were no other associated symptoms , co - morbidities and he was nonalcoholic and non - smoker .
general physical examination revealed no abnormality , and on abdomen examination there was a firm , nontender , 88 cm retroperitoneal lump , with well - defined margins , in epigastrc region and also occupying part of left hypochondrial and umbilical region , with no organomegaly and no free fluid .
ultrasonography of the abdomen showed a large 7.76.48.4 cm size heterogeneously hypoechoic mass , involving the body of pancreas , while the head of the pancreas , liver , spleen and other organs were normal .
contrast enhanced computed tomography showed a large , heterogeneously enhancing , well defined intrapancreatic lesion , of size 127.5 cm in body and tail region , with few small non - enhancing areas , indentation on posterior wall stomach , and loss of intervening fat plane ( figure 1 ) .
there were no evidence of ascites , liver and peritoneal metastasis , and peripancreatic and retroperitoneal lymphadenopathy .
oesopha - gogastroduodenoscopy showed the presence of extrinsic impression on the posterior wall of gastric body .
colonoscopy and tumor marker ca 19 - 9 were normal . in view of a large mass involving the body of the pancreas and no evidence of metastasis , after adequate preoperative preparation
intra - operatively , there was a large mass of size 128 cm arising from the body and part of tail of pancreas , abutting splenic vessels and transverse mesocolon while pancreatic head was normal .
the mass was free from stomach , transverse colon , duodenum and spleen ( figure 2 ) , and there were no palpable lymph nodes , liver and peritoneal metastasis and ascites .
on histopathological examination , grossly , well circumscribed grey brown soft tissue mass measuring 1288 cm , with multinodular external surface , and cut section was variegated with layers of hemorrhage and necrosis , and on microscopy , there was partly encapsulated tumor composed of cells arranged mainly in diffuse sheets , trabecular and focally in acinar pattern , at places tumor sheets are separated by thick fibrous septa and cells shows mild pleomorphism , round in shape , with indistinct cell membranes , moderate amount of granular eosinophilic cytoplasm , round to oval hyperchromatic nuclei ( figure 3a ) .
periodic acid - schiff ( pas ) staining with diastase showed granular cytoplasmic positivity ( figure 3b ) , and immunohistochemistry demonstrated acinar enzymes , trypsin and chymotrypsin .
post - operative period was uneventful and the patient received 6 cycles of chemotherapy ( folfox regimen ) and got discharged on post - operative day 18 .
acinar cell carcinoma is a rare pancreatic malignancy , and constitutes 1 - 2% of all exocrine pancreatic neoplasms in adults and 15% of those in pediatric age group of all pancreatic tumors .
though acinar cells makeup the bulk of the pancreas , pancreatic neoplasms exhibiting predominantly acinar differentiation are rare . not more than 25% of the neoplastic cells
exhibit endocrine or ductal components and cases with significant endocrine or ductal components ( more than 25% ) are regarded as mixed carcinomas .
there is a slight male preponderance and mostly presents in 5 to 7 decades of life .
acinar cell carcinomas arise more commonly from head though they may arise from any part of the pancreas . most commonly , acinar cell carcinomas present with non - specific symptoms like weight loss ( 52% ) , abdominal pain ( 32% ) , nausea and vomiting ( 20% ) ,
in contrast to ductal adenocarcinoma , acinar cell carcinoma rarely obstructs the common bile duct because they generally compress and do not infiltrate into adjacent structures , so jaundice is infrequent ( 12% ) . our patient presented with chronic diarrhea and upper abdominal pain .
paraneoplastic syndrome may be the only presenting symptom in 15% of patients , and lipase hypersecretion syndrome 
  characterized by subcutaneous fat necrosis , polyarthralgia and peripheral eosinophilia is a type of paraneoplastic syndrome associated with it .
this syndrome is more commonly encountered in patients with hepatic metastasis , although occasionally this could be due to an extremely large organ - limited primary carcinoma .  
successful surgical removal of the neoplasm may result in the normalization of the serum lipase levels and resolution of the symptoms .
serum glycoprotein markers ( ca 19 - 9 ) are usually not elevated and a modest elevation in serum lipase levels may be detected in those patients without the lipase hypersecretion syndrome .
analyzed cell lineage markers , p53 expression , and k - ras mutations of acinar cell carcinoma , demonstrating that they constitute an entity different from ductal adenocarcinoma or endocrine tumors . in recent molecular analysis of acinar cell carcinomas , it was found that there are abnormalities in the apc/catenin pathway similar to those found in colorectal cancer .
for this reason , chemotherapeutic agents effective in pancreatic adenocarcinoma and colorectal carcinoma like gemcitabine , cisplatin , 5fu , leucovorin , oxaloplatin , irinotecan , capecitabine etc .
are effective in acinar cell carcinoma , and we also gave our patient folfox regimen .
four patterns of growth have been described : acinar , cellular , trabecular , and glandular . in our case , it was mixed acinar and trabecular pattern .
acinar enzymes , especially trypsin , chymotrypsin are demonstrable by immunohistochemistry in essentially all cases . in most of the studies , approximately 50% cases presented with metastasis at the time of diagnosis and
it is different from adenocarcinoma in that it has more indolent course with 5-year survival over 40% , with median survival 36 month , and the genetic alteration of ductal adenocarcinoma like kras , tp53 , p16 , or smad4 are absent in acinar cell carcinomas . in conclusion ,
acinar cell carcinomas are rare pancreatic tumors , present mostly with non - specific symptoms , difficult to diagnose pre - operatively , surgery is the mainstay of therapy , and there are no standard chemotherapy regimens and prognosis is better than adenocarcinomas .
 acinar cell carcinoma of the pancreas is a rare pancreatic malignancy , constituting only 1 - 2% of all the pancreatic tumors . 
 a young adult male presented with chronic diarrhea and upper abdominal pain , on investigations was found to have a large pancreatic tumor of size 127.5 cm involving the body of the pancreas . 
 pancreatic body and tail resection with splenectomy was done and final histopathological examination showed acinar cell carcinoma of the pancreas . 
 prognosis of acinar cell carcinoma is better than adenocarcinoma of the pancreas . 
Introduction
Case Report
Discussion