Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) of pancreas: a rare entity

Abstract

Introduction: Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) comprise of both epithelial and neuroendocrine component in which each element has to comprise at least 30% of the tumor. MiNEN usually involve various gastrointestinal organs, however it is very infrequent in pancreas. Case Presentation: We encountered an 81-year-old male patient who presented with pain in upper abdomen since 3 months. He noticed jaundice with cholestatic features for last 15 days which was associated with anorexia and weight loss. Liver function test revealed: Bilirubin-3.8mg/dl; AST- 76 U/L; ALT- 163 U/L; Alkaline phosphatase- 826 IU/L, while carbohydrate antigen 19-9 was 46.9 U/ml. CECT abdomen reported a mass in the pancreatic head with dilated common bile duct and pancreatic duct. He underwent pancreatoduodenectomy (PD) with uneventful post-operative course. Histopathological examination revealed two different tumours: ductal adenocarcinoma admixed with neuroendocrine tumour of pancreas which was confirmed with immunohistochemistry (CK-7, Chromogranin and Synaptophysin positive). He received adjuvant chemotherapy and at the end of six months follow up, he has no recurrence. Conclusion: MiNEN is a rare malignancy of pancreas for which pancreatoduodenectomy was performed and diagnosis confirmed on histopathology with immunohistochemistry. It is important to share all individual experience-based information of such anecdotal cases to get knowledge about their clinical and biological behaviour and to standardize optimal therapy.