Breast metastases of gastric signet ring cell carcinoma: a differential diagnosis with primary breast signet ring cell carcinoma.

Metastatic deposits within the breast may be difficult to distinguish from primary breast carcinoma. Radiological features and immunohistochemistry especially for steroid hormone receptors and expression of gross cystic disease fluid protein may be helpful in differentiating these two conditions. In this report, we present a case of signet ring cell stomach cancer with metastasis to the breast and discuss the differential diagnostic options.