[Synchronous medullary and mucinous tumor in the right colon: case report].

Colon cancer according to the World Health Organization is classified histologically as: adenocarcinoma in 95%, mucinous adenocarcinoma 3.9-19%, signet ring cell carcinoma 1-2%, small cell carcinoma less than 1%, medullary carcinoma in less than 1%, undifferentiated carcinoma and neuroendocrine carcinoma 1-2%. Medullary and mucinous carcinoma usually occur in the right colon predominantly in females and are associated with microsatellite instability. The incidence of synchronous colorectal tumors varies between 1.3 and 7.3%, 43% of them are located proximal to the main lesion and one third are advanced tumors. To our knowledge there are no reports of synchrony in the right colon. Objective: To present a case report. Clinical Case: Patient operated for a right colon tumor diagnosed by videocolonoscopy, presenting in the anatomopathological study two tumors, one of mucinous origin and the other a synchronous medullary tumor. Conclusion: This case reveals the importance of correlating endoscopic findings with the anatomopathological study of the surgical specimen, since videocolonoscopy can underdiagnose synchronous tumors, particularly those located in the right colon.