Adenosquamous carcinoma of the sigmoid colon treated by the less invasive procedures of endoscopy and laparoscopy: report of a case.

A 51-year-old man demonstrated a positive finding for a fecal occult blood test during a screening examination. Total colonoscopy was therefore performed, and a semi-pedunculated polyp was detected in the sigmoid colon. Although this polyp was suspected of invading the submucosal layer, it was removed endoscopically because the preoperative diagnosis was well-differentiated adenocarcinoma. The pathological findings revealed adenosquamous carcinoma that had invaded the submucosal layer with lymphatic invasion. A laparoscopic bowel resection was then performed and a histopathological examination of the surgical specimen showed metastasis to two regional lymph nodes. The patient is alive and recurrence-free 22 months after the operation. Adenosquamous carcinoma has been reported to be rare and to possess a highly metastatic potential. It consists of both squamous cells and glandular cell components. We report a case of adenosquamous carcinoma of the sigmoid colon treated by less invasive approaches consisting of an endoscopic mucosal resection and a subsequent laparoscopic colectomy.