Mammary analogue secretory carcinoma of salivary glands is a lipid‐rich tumour, and adipophilin can be valuable in its identification

Abstract

MASC is a lipid-rich tumour containing large lipid droplets covered by adipophilin. This finding can be included among its defining immunohistochemical features, and possibly represents lactation-like secretory differentiation. Strong expression of STAT5a and cytoplasmic p63 in MASC reinforces this hypothesis.

Cytogenetic and immunohistochemical characterization of mammary analogue secretory carcinoma of salivary glands

“…Furthermore, a recent study has shown that mammaglobin expression in MASC can be variable with complete lack of expression in a small subset [23]. This is further illustrated by the fact that one of our cases with rearranged ETV6 showed no mammaglobin expression.…”

“…Similarly, Carbonic anhydrase VI has recently been reported as an acinar marker and was shown to differentiate MASC from ACC with a sensitivity and specificity similar to DOG1 [38]. These findings suggest potential use of these markers as immunohistochemical tools [23]. Furthermore, two cases of non-NTRK gene fusion with ETV6 (ETV6-X fusion) have also been reported which appears to correlate with more aggressive histological features such as PNI and LVI [39].…”

“…A recent study analysed adipophilin (a lipid marker) expression in MASC showing larger lipid droplets in MASC compared to other salivary tumours [23]. Similarly, Carbonic anhydrase VI has recently been reported as an acinar marker and was shown to differentiate MASC from ACC with a sensitivity and specificity similar to DOG1 [38].…”

Salivary Gland Tumor “Wishes” to Add to the Next WHO Tumor Classification: Sclerosing Polycystic Adenosis, Mammary Analogue Secretory Carcinoma, Cribriform Adenocarcinoma of the Tongue and Other Sites, and Mucinous Variant of Myoepithelioma

“…These tumors were termed mammary analogue secretory carcinomas (MASC). Since this initial report, there have been approximately 100 additional cases published [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. These have been previously diagnosed as unusual variants of acinic cell carcinoma, adenoid cystic carcinoma, cystadenocarcinoma, mucoepidermoid carcinoma or adenocarcinoma, NOS.…”

“…The proliferative rate ranges from 5 to 28 % [20]. Several recent studies demonstrated that the combination of S100, mammoglobin and especially large vacuole adipophilin staining is very helpful to eliminate almost all of the other differential diagnostic mimics of mammary analogue secretory carcinoma [24,27,30,39]. This latter stain is important, as occasionally mammoglobin, similar to acinic cell carcinoma, is only focally positive in MASC.…”