We present an unusual case of colon cancer development in bowel segment involved with lobular breast carcinoma infiltration. 80 year old Caucasian woman was diagnosed with right colon carcinoma due to rectal bleeding and obstructive symptoms. She had nine years clinical history of lobular, well differentiated breast cancer with five years of postoperative tamoxifen therapy, disseminating to bones and pleural cavities two years prior to hemicolectomy. On microscopic examination under the colonic adenocarcinoma and in the whole length of the resected bowel segment, massive infiltration of lobular carcinoma was discovered. She remains alive under the palliative hormone and chemotherapy. In our paper we discuss clinical and pathological issues concerning metastases of breast cancer into the gastrointestinal tract as well as rare colocalization of colonic and breast cancers within the same intestinal segment. Review of the literature is also presented accordingly.
Keywords: Lobular breast carcinoma; coexistence; colonic adenocarcinoma; diagnosis.