Breast metastasis of gastric signet-ring cell carcinoma: a case report and literature review

Chun-Lan He, Ping Chen, Bing-Lan Xia, Qin Xiao, Feng-Lin Cai

Cases of primary gastric adenocarcinoma with metastasis to the breast are extremely rare. Till now, only 38 cases have been reported in PubMed since 1908. We herein reported a race case of gastric adenocarcinoma with metastasis to the right breast. Breast biopsy showed invasive signet-ring cell breast carcinoma in the right breast. She was given a TEC regimen (docetaxel 75 mg/m(2), epirubicin 75 mg/m(2), and cyclophosphamide 600 mg/m(2) every 3 weeks) for one cycle but showed no objective response. Upper gastrointestinal endoscopy demonstrated an ulcerative mass in the gastric body. Biopsy demonstrated low-grade gastric adenocarcinoma with signet-ring features. In immunohistochemistry, mammary malignant cells were positive for cytokeratin 7, cytokeratin 20, villin, and ErbB2/HER2, but negative for gross cystic disease fluid protein-15, estrogen receptor, and progesterone receptor. The diagnosis of metastatic poorly differentiated signet-ring cell adenocarcinoma of the right breast identical to gastric primary was confirmed finally. Gastric cancer with metastasis to the breast can be diagnosed by clinical history, histological findings, and immunohistochemical markers.