Mammary analogue secretory carcinoma of the parotid: An arduous maze to solve

ABSTRACT

Mammary analogue secretory carcinoma (MASC) is an unusual and rare salivary gland malignancy that recapitulates the genetic and microscopic features of secretory carcinoma of the breast (SCB) which is an equally rare entity. MASC and SCB express S-100 protein, vimentin, mammaglobin, and harbor a t (12; 15) (p13; q25) translocation which leads to ETV6-NTRK3 fusion product. The morphology of MASC is not specific and can overlap with many salivary gland tumors. S100 and mammaglobin抯 strong positivity confirm the diagnosis of MASC. The morphology along with immunohistochemical findings provides important clues for diagnosis. Recent advances in molecular pathology help in investigating both differential diagnosis and prognosis in salivary gland oncology. Molecular testing is recommended to arrive at a diagnosis of MASC. We report a case of MASC of the parotid gland in a 47-year-old male patient with his immunohistochemical profile.