Solitary papillary breast carcinoma metastasis to the large bowel presenting as primary colon carcinoma: case report and review of the literature.

Breast carcinoma has the potential for widespread dissemination. Spread to the lower gastrointestinal tract is infrequent, often multifocal, occurs in association with spread to other sites, and most commonly develops from lobular carcinoma. Solitary colorectal metastasis as the first and sole manifestation of spread is a rare occurrence and can be confused with primary intestinal malignancy. We present a case of metastatic papillary breast carcinoma presenting as a perforated primary colon cancer. Identity of the lesion was confirmed by direct histologic comparison of the resected tumor with prior breast specimen, cytokeratin expression, and the presence of estrogen receptors.