A rare case of a recently described entity: mammary analogue secretory carcinoma (MASC) of the parotid gland

MASC is a salivary gland tumour which shares histological, immunologic and genetic characteristics with mammary secretory carcinoma including an ETV6 translocation and immunocytochemical positivity for S-100 protein, CK7, and mammaglobin as well as negativity for DOG1. This is a rare tumour with uncommon characteristics when compared to other salivary gland tumours. The case reported here is of a 28-year-old female patient who presented in the ER due to a palpable mass in the left parotid region. She underwent a superficial parotidectomy with using a mini-lifting approach, with tumour resection, followed by radiotherapy. The identified tumour shared most of the clinical characteristics with other cases of MASC described in the literature.