Abstract
A 75-year-old man was admitted to our hospital for close examination of transverse colon cancer. Colonoscopy revealed a submucosal tumor-like, elevated lesion, 10mm in diameter, with an irregular depression at the top of the tumor. Magnifying colonoscopy detected a type I-like round pit and a type IIIL-like pit in the depressed area. Biopsied specimens showed signet ring cell carcinoma with mucinous carcinoma in the mucosal layer, and laparoscopic transverse colectomy was performed. Histopathological findings showed well differentiated tubular adenocarcinoma in the depressed area, and signet ring cell carcinoma had invaded the mucosal layer and the submucosal layer. The histopathological diagnosis was adenocarcinoma (muc>sig>tub1), pT1 (SM), ly2, v1, pN0. The patient is alive in good health 13 months after the operation. There have only been a few reports on primary mucinous carcinoma of the colon with signet ring cell carcinoma.
