Mammary analog secretory carcinoma of salivary glands: a report of 2 cases in the lips

ObjectiveThis study presents 2 cases of labial mammary analog secretory carcinoma (MASC) including diagnostic criteria and a review of literature. MASC has not been previously described in the dental literature.DesignTwo cases of MASC and 1 case of acinic cell carcinoma (ACC) of the lips were reviewed for their microscopic and immunohistochemical features. Fluorescence in situ hybridization (FISH) for the ETV6–NTRK3 translocation was performed. The clinical features of 65 cases previously described in the medical literature are reviewed.ResultsMASCs had hematoxylin and eosin features similar to those of ACC but demonstrated larger, globular periodic acid–Schiff positive deposits, whereas ACC had finer granular deposits. MASCs were strongly positive for S100, vimentin, and mammaglobin, whereas ACC was negative for S100 and vimentin and only focally mammaglobin positive. FISH demonstrated that MASCs were positive for ETV6 disruption.ConclusionMASCs are newly described, can occur in a wide age range, favor males, and can be misinterpreted as ACC or adenocarcinoma not otherwise specified by routine microscopy.