Incidental cystic endocrine tumor of the pancreas: a case report with immunohistochemical study.

A large cystic lesion in the pancreatic tail was found incidentally in a 20-year-old female during laparoscopic cholecystectomy. Pre-operative work up had revealed calculi in gall bladder and in addition, a cystic lesion in pancreas suggesting the possibility of a pseudocyst. A laparoscopic enucleation of the cyst was performed along with the removal of gallbladder. Microscopic examination of the resected specimen revealed a pancreatic cystic endocrine tumor; however, this tumor had produced no symptoms. Immunohistochemical studies of the tumor cells showed positivity for neuron-specific enolase, chromogranin A, and synaptophysin indicating their neuroendocrine nature. Prognostic markers (CK19, CD10 and Ki67) indicated good prognosis. Although endocrine tumors of the pancreas are usually solid, cystic change occurs only rarely and such tumors should be considered in the differential diagnosis of patients who have a cystic lesion in the pancreas in view of their rare transformation into a malignant tumor.