Carcinoma in villous adenoma of ascending colon associated with sarcoid reaction in the regional lymph nodes.

A 79-year-old woman was admitted to our hospital due to continuous anal bleeding. Colonoscopy showed a huge villous tumor on the middle area of the ascending colon. A typical right colectomy and lymph node dissection were performed. The resected specimen showed a villous type tumor located on the ascending colon. The histopathologic investigation demonstrated a moderately differentiated adenocarcinoma arising in a tubulovillous adenoma and extending to the submucosa. Although there was no evidence of metastatic carcinoma in the dissected lymph nodes, epithelioid cell granulomas with multinucleated giant cells lacking in the central caseous necrosis suggested sarcoid reaction.