Abstract
Background : Primary signet-ring cell carcinoma of breast is a rare tumor. We report the results of cytomorphological, immunohistochemical, and ultrastructural studies in a case of pure ductal signet-ring cell carcinoma originating in the breast.
Case : A 70-year-old woman admitted for a palpable left breast mass found in fine-needle aspiration cytology to consist of signet-ring cells, necessitating modified radical left-breast mastectomy. Histopathological, immunohistochemical staining, and ultrastructural findings indicating primary pure signet-ring cell carcinoma of the breast from ductal carcinoma.
Conclusion : Primary signet-ring cell carcinoma of the breast is rare, with 100 cases reported in the Japanese literature. Our case is, to our knowledge, the first report of microinvasive signet-ring cell carcinoma of the breast. We found fine-needle aspiration cytology to be simple and useful in detecting signet-ring cell carcinoma cells.
