Intramural colonic splenosis: a rare case of lower gastrointestinal bleeding

A 41-year-old man had left upper quadrant abdominal pain, constipation, and melena. About 6 years previously, he received a single gunshot wound to the abdomen, which required partial gastrectomy and small bowel resection. He subsequently developed bleeding gastric varices for which he underwent a splenectomy 2 years before the current admission.

A CT scan identified a 6.5 × 2.5 cm left upper quadrant mass. Upper endoscopy was unremarkable, but on colonoscopy, a 3-cm polypoid mass partially obstructed the descending colon. A left hemicolectomy was performed with a primary colonic anastomosis and incidental appendectomy. The mass involved the muscularis of the colon and caused ulceration of the mucosa was ectopic hyperplasic splenic tissue, indicating intramural colonic splenosis. We hypothesize that after the patient's splenectomy, a colonic focus of heterotrophic spleen became hyperplastic and led to a clinically apparent lesion.