Radiology-Pathology Conference: carcinosarcoma of the colon.

Carcinosarcomas are very uncommon tumors, which are comprised of both malignant epithelial and mesenchymal elements. They occur most commonly in the head and neck, respiratory tract, and female reproductive organs. In the gastrointestinal tract, they are most often found in the oropharynx, esophagus, and, to a lesser extent, in the stomach. Carcinosarcomas rarely originate from the colon, but when they do, they are extremely aggressive malignancies. We report the radiologic and pathologic findings of a patient with a carcinosarcoma believed to have arisen from the colon and which involved the adjacent mesentery and omentum.