Acinic cell carcinoma of the breast: an immunohistochemical and ultrastructural study

The clinicopathological features of six cases of breast carcinomas showing features of acinic cell differentiation, which are similar to those seen in homologous tumors of salivary glands, are presented. The patients, all wom en, were 35-80 years of age. One case recurred after 4 years, and in two ca ses axillary lymphnode metastases were found at the time of surgery. Histol ogically the tumors showed a microglandular pattern merging with solid area s. Cytologically, immunohistochemically, and ultrastructurally the tumors w ere very similar to cases of acinic cell carcinoma of the parotid gland. Th e differential diagnostic criteria with microglandular adenosis and carcino mas showing granular cytoplasm are discussed. It seems that acinic cell car cinomas of the breast have to be added to the long list of tumors that affe ct the salivary glands and can also arise in the breast.