Abstract
Breast cancer metastasis to the gastrointestinal lesion is rare. We report a case of rectum and stomach metastasis from invasive lobular carcinoma. A 58-year-old woman came to our hospital for therapy for multiple liver and bone metastasis. She had undergone modified radical mastectomy with axillary lymph node dissection for left breast cancer 8 years earlier. The final diagnosis was invasive lobular carcinoma (T2N1M0 Stage IIB), estrogen receptor (+) and progesterone receptor (-). She underwent 6 courses of chemotherapy with CMF (cyclophosphamide, methotrexate, and 5FU) and hormone therapy with tamoxifen for 2 years after surgery. She underwent radiation therapy and chemotherapy with EC at our hospital for the multiple liver and bone metastasis of the breast carcinoma. During chemotherapy, she developed low abdominal pain and diarrhea and passed bloody stools. Endoscopic examinations revealed a stenotic lesion in the rectum and multiple erosive lesions in the stomach. Biopsy specimens of the rectum and stomach suggested poorly differentiated adenocarcinoma with signet-ring cells. Based on the clinical course and endoscopic examinations, the lesions of the rectum and stomach suggested metastatic breast cancer. The immunochemical studies (CK7, CK20, E-cadherin, GCDFP-15, and 34βE12) confirmed that the lesions of the rectum and stomach were metastasis of invasive lobular carcinoma of the breast.
