Mammary analog secretory carcinoma of salivary glands: Review of a new entity with an emphasis on differential diagnosis

Mammary analog secretory carcinoma (MASC) is a newly described neoplasm of the major minor salivary glands that is characterized by considerable morphologic, immunophenotypic, and genetic similarities to secretory carcinoma of the breast. Since its initial description in 2010, the number of reported MASCs has grown considerably; it is probably not as rare as was initially believed. As experience with MASC has grown, its clinical histological spectra have come increasingly into focus. This article presents an illustrative case of MASC, followed by a review of its defining features. Finally, the differential diagnosis will be discussed along with strategies to resolve diagnostic dilemmas.