Mammary analogue secretory carcinoma (MASC) of parotid gland- A case report

Abstract

Mammary analogue secretory carcinoma is a rare salivary gland carcinoma which shares morphologic and immunohistochemical features with the secretory carcinoma of breast and was first proposed by Skalova in 2010 with translocation of (q13; q25), t (12; 15), subsequently giving ETV6-NTRK3 gene rearrangement. Usually, it is a benign tumor that affects the parotid gland, with slight predilection for males. The present article report a case of secretory carcinoma of right parotid gland with special emphasis on histological feature and immunohistochemistry for diagnostic purpose and its management. Differential diagnosis includes AciCC, ADC-NOS and MEC. In a review by Chiosa et al (2012) in 337 cases of salivary gland malignancy included AciCC, ADC-NOS, MEC, LGCC, non-ITAC, signet ring adenocarcinoma, PLGA and most common malignancy reclassified as MASC were AciCC (11/89), ADC-NOS (14/37), MEC (1/165). Management for MASC includes surgical excision of the lesion (either superficial or total parotidectomy) for local, less aggressive disease like for low-grade malignant salivary gland neoplasms. For more invasive, metastatic disease and positive margins- neck dissection, radiotherapy and chemotherapy are reserved. There is no standard multidisciplinary treatment protocol established due to scarcity of this disease.