A Case of Breast Metastasis of Primary Colorectal Cancer

Abstract

A 64-year-old woman was referred to our hospital with a palpable mass in her left breast. Mammography and ultrasonography showed a 40-mm, well-circumscribed mass with axillary lymphadenopathy. A core needle biopsy of the mass was done, which was diagnosed as adenocarcinoma. PET-CT scan showed a large, 80-mm mass with abnormal FDG accumulation in the ileocecal region, and lower endoscopy was performed. A circumferential protuberant lesion was found in the ascending colon, and the diagnosis of adenocarcinoma was confirmed by biopsy. The diagnosis of ascending colon cancer with breast and axillary lymph node metastases, cT2N1M1b, cStage IVb, was first considered based on the imaging and pathological findings, but overlapping cancers could not be ruled out. Partial mastectomy, axillary lymph node dissection, laparoscopic right hemicolectomy, and D3 lymph node dissection were performed due to the rapid growth of the breast lesion. Based on the surgical pathology, she was diagnosed with advanced colorectal cancer with breast metastasis. Since solitary breast metastases are extremely rare as distant metastases in colorectal cancer, this case is reported along with a literature review.