A Diagnostic Surprise For A Right Iliac Fossa Mass - A Perforated Ileal Gastrointestinal Stromal Tumour.

Gastrointestinal Stromal Tumours (GISTs) are tumours of the gut found mostly in stomach and small intestine. The complications are Gastrointestinal (GI) bleeding, obstruction, pain and rarely perforation. We are reporting an abnormal presentation of GIST masquerading as an acute abdomen with Right Iliac Fossa (RIF) mass in 60-year-old lady. Contrast Enhanced Computed Tomography (CECT) of abdomen revealed a peripherally enhancing encapsulated abscess in RIF in close contact with base of caecum and adjacent peritonitis suggesting caecal perforation. On laparotomy, a gangrenous perforated ileal GIST was identified along the antimesenteric border of ileum. Pathological examination confirmed the tumour to be a GIST of spindle cell type, further reiterated by immunohistochemistry. Our case report emphasizes, GIST as a rare and unusual differential diagnosis of RIF mass, and to have high degree of clinical suspicion when a similar situation is encountered in an emergency scenario, keeping in mind the poor outcome due to delay in appropriate management of the disease.