Gastrointestinal stromal tumor of the duodenum presenting as a large pancreatic head mass: a case report

ABSTRACT Introduction Duodenal gastrointestinal stromal tumors (GISTs) are rare, accounting for only 3–5% of all GISTs. These tumors occasionally grow outward and compress adjacent structures such as the pancreas, mimicking a primary pancreatic neoplasm. Case presentation We report the case of a 69-year-old female who presented with progressive jaundice, epigastric pain, and weight loss. Imaging revealed a 40 × 48 mm heterogeneous mass located at the pancreatic head, Whipple procedure. Clinical discussion Histopathology and immunohistochemistry confirmed the diagnosis of a duodenal GIST, positive for CD117, CD34, DOG-1, and Ki-67. The patient had an uneventful recovery and was referred for oncologic follow-up. Conclusion This case highlights the importance of considering GISTs in the differential diagnosis of pancreatic masses.