Large Duodenal Gastrointestinal Stromal Tumour Invading the Pancreas- A Masquerader for Pancreatic Head Mass

Abstract

Gastrointestinal Stromal Tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract commonly arising from stomach and small intestine. Duodenal GISTs are rare. Though uncommon, GISTs can arise from the omentum, mesentery, gallbladder as well as retroperitoneum and are defined as Extra GISTs (EGIST). Authors have reported a case of large GIST arising from the second part of the duodenum and mimicking the large pancreatic head mass in a 34-year-old female patient presented with abdominal pain and vomitings. The Contrast Enhanced Computed Tomography (CECT) revealed a large enhancing mass in the pancreatico-duodenal groove not separated from pancreatic head. Whipple’s surgery was performed. Histopathology and Immuno-histochemistry report revealed the duodenal GIST with pancreatic infiltration with high risk for metastases according to mitotic index and size. Sometimes large duodenal GISTs can make the diagnosis difficult radiologically due to invasion of pancreatic head and mimic as primary pancreatic head tumour.