# An unusual case of incidental pancreatic neuroendocrine tumor presenting with main pancreatic duct cystic dilatation

## TL;DR

A rare case of a pancreatic tumor was misdiagnosed as a pseudocyst, highlighting challenges in diagnosing small pancreatic tumors.

## Contribution

This case report presents a unique diagnostic challenge of a pancreatic neuroendocrine tumor mimicking a pseudocyst.

## Key findings

- A pancreatic neuroendocrine tumor was found to cause main pancreatic duct dilatation and sacculation.
- Initial imaging misdiagnosed the tumor as a pseudocyst or intra-ductal papillary mucinous neoplasm.
- The case emphasizes the difficulty in diagnosing small asymptomatic pancreatic tumors with limited imaging.

## Abstract

Introduction: Pancreatic lesions have varied morphology and presentation making their diagnosis challenging. The lesions may be asymptomatic incidentalomas on abdominal imaging for other conditions, symptomatic producing specific hormone effects or causing local effects. Case: We report a 35-year-old woman with recurrent abdominal pain confirmed gastroesophageal reflux disease. Initial CT imaging reported findings of a pancreatic pseudocysts. A careful review of the imaging showed cystic dilatation of the main pancreatic duct mimicking a main pancreatic duct intra-ductal papillary mucinous neoplasm. At surgery, a small nodule palpated in the pancreatic head with sacculation in the body and tail. A histopathological review showed a pancreatic neuroendocrine tumour blocking the main pancreatic duct at the neck causing downstream dilatation and sacculation. This case highlights the difficulty of diagnosing small asymptomatic pancreatic tumours especially with limited range of imaging modalities while increasing awareness of these conditions to improve our ability to manage them effectively.