Colonic composite tumors are uncommon masses composed of endo- and exocrine cells. Treatment is similar to that of adenocarcinomas. We report the case of a 44-year-old woman who consulted for abdominal pain. A computed tomography (CT) scan showed a tumor at the splenic flexure bowel and 2 hepatic nodules, suggesting metastases. Preoperative biopsies confirmed an adenocarcinoma. The patient underwent surgery, which confirmed the CT findings. Extended right colectomy was performed, followed by an ileal-sigmoid anastomosis, resection of a diaphragm segment, and resection of both hepatic metastases. The patient made a good postoperative recovery. Histological analysis showed moderately differentiated tubular adenocarcinoma combined with a poorly differentiated neuroendocrine carcinoma and metastases in 25 of 28 lymph nodes. The 2 hepatic metastases showed areas of poorly differentiated neuroendocrine carcinoma. The patient is currently asymptomatic and is undergoing chemotherapy.