Contributor: Gordon K. Klintworth
Adenocarcinoma of the colon is a common malignant neoplasm. Most arise in the rectum or sigmoid colon. Carcinoma of the colon is often associated with a positive family history and ~10% of colon carcinomas are believed to have a genetic predisposition. Mutations in certain tumor suppressor genes (APC, DCC) predispose to colon carcinoma. In countries where Schistosoma japonicum is prevalent an infection with this parasite [schistosomiasis] is associated with carcinoma of the colon. Adenocarcinoma of the colon often metastases locally as well as to regional lymph nodes and hematogenously to distant sites. The tumor can metastastize to the eye,orbit or other ocular adnexal structures [carcinoma - metastatic]. Colon carcinoma is the most common metastatic tumor  to the ovary and is often confused with an endometrioid carcinoma [carcinoma - endometrioid].