MR imaging findings of a rare pediatric parotid tumor: Mammary analogue secretory carcinoma.

We present magnetic resonance imaging findings of an 11-year-old girl with a mammary analogue secretory carcinoma (MASC) of the parotid gland. MASC is a recently described tumor of the salivary glands that is genetically and histologically similar to secretory breast carcinoma. To date, a few cases have been reported in the pediatric population, with limited information of its imaging characteristics. We suggest that decreased T2 signal of the solid component of the MASC representing cellular components with associated complex cystic parts may be a helpful imaging finding and can make a substantial contribution in differentiating this new entity from other rare pediatric parotid masses. Although there are no characteristic imaging findings at this time, MASC should be considered in the differential of salivary gland tumors in the pediatric population as well.