A case report of multiple bilateral breast metastases after colorectal cancer

Although primary breast cancer is the most common tumor in women, breast metastases are rare findings. We report the first case in English literature with CRC metastases to the breast and adrenal gland concurrently.

A 42-year-old Caucasian female complained of abdominal pain over the last 3 days. Her history was remarkable for stage 2 colon cancer and she was free of disease for 2 years before the presentation, due to receiving Surgical-chemotherapy. The radiologic investigation showed a well-defined cystic mass in the left adrenal gland and left breast nodule. After adrenalectomy, the diagnosis of the mass was metastatic mucinous adenocarcinoma. During the surgical preparation, bilateral breast lumps were noticed. Histopathology of breast mass showed mucinous adenocarcinoma. Immunohistochemical staining revealed that the neoplastic gland was positive for CDX2, CK20, and P53 mutation and negative for CK7, PR, ER, and HER2. Overall, the diagnosis was metastatic colorectal adenocarcinoma to the breast.

Metastatic lesions in the adrenal gland tend to be bilateral with irregular shape. Breast metastases are singular unilateral lesions with predominance in the left breast. Biopsy and immunohistochemistry make the final diagnosis. The management plan is complex and depends on many factors like the general condition of the patient and the presence of other metastases. However, breast metastases may be a clinical clue to disseminated disease.

Breast metastases should be in the differential diagnosis in patients with a history of colorectal adenocarcinoma, in order to provide the appropriate clinical care.