Small cell carcinoma of the colon arising in a carcinoid tumor

Small cell carcinomas of the gastrointestinal tract are rare and clinically aggressive tumors. A case is presented of a 70 year-old woman who presented with small bowel obstruction and was found to have a cecal mass. She underwent right hemicolectomy, and histopathology showed a small cell carcinoma arising in the background of a carcinoid tumor. Although small cell carcinomas of the colon have frequently been found in association with colonic adenomas, this appears to be the first report of a low-grade carcinoid tumor in combination with a small cell carcinoma.