Unusual Primary Subepithelial Tumors of the Colon: Multimodality Imaging Findings with Endoscopic and Pathologic Correlation

Colonic subepithelial tumors are rare, and therefore, are not encountered as often in daily practice as are adenomas and carcinomas of the colon. Furthermore, they may not cause symptoms before attaining large size. When small in size, colonic subepithelial tumors are incidentally detected on a colonoscopy or cross-sectional images. A wide variety of benign and malignant primary subepithelial tumors may arise from the colonic wall. Some tumors such as lipomas, neuroendocrine tumors, hemangiomas, and lymphomas originate in the superficial location on the colon wall. Other tumors such as a gastrointestinal stromal tumor (GIST) arise from the deeper part of the muscularis propria and often demonstrate an exoenteric growth pattern (1). In this article, we present a variety of radiologic findings from benign and malignant subepithelial tumors of the colon, and correlate them with their corresponding colonoscopic and pathologic findings.