An 81-year-old woman with no relevant medical history was admitted to our hospital for severe hematochezia (Hb 7.9 g/dl).
No lesions were found in upper endoscopy.
However, after hemodynamic stabilization, an ulcerated lesion was observed in the descending colon, with a submucosal aspect, about 12 mm in diameter, located within a diverticular formation of the colon.
The opaque enema demonstrated the existence of a colonic duplication at this level, simulating a large diverticulum, with a fixed lesion at its upper edge.
Abdominal CT showed no other lesions.
The histological diagnosis obtained by endoscopic biopsies was colon GIST.
After surgical evaluation, segmental colonic resection was performed laparoscopically.
The specimen obtained contained a 32 x 30 mm colonic duplication with a hard 12 x 7 mm grey nodule in its interior. Histologically this nodule was a calcified colonic GIST with a mitotic index of 5 x 7 mm.
The patient remains asymptomatic 7 months after surgery.
