A pedunculated adenomatous polyp of the descending colon containing benign glandular epithelium deep within the stalk is described. The submucosal cysts resemble colitis cystica profunda except that the lesion is confined to a solitary pedunculated polyp. Lesions of either localized colitis cystica profunda or adenomatous polyp with submucosal cysts have been misdiagnosed as adenocarcinoma. Attention to the cytologic details of the submucosal component should prevent this misinterpretation.