An unusual presentation of colon cancer.

A rare case of asymptomatic cancer of the ascending colon presenting as a subcutaneous groin mass is reported. At the time of right hemicolectomy with resection of the groin mass there was no sign of incontinuity spread or lymph blockage. Sequential determination of carcinoembryonic antigen levels (CEA) in serum reflected the reduction in tumor mass after surgery as well as subsequent recurrences of disease in the groin and in the lung after 2 years. Immunoperoxidase staining of the primary tumor and the metastases showed strong positivity for CEA confirming the origin of the serum CEA. There have been no signs of liver involvement. The route of spread of this unusual metastasis is not known.