Beautiful example of a secretory carcinoma of the salivary gland. Secretory carcinoma (aka mammary analogue secretory carcinoma) is a ~recently described malignant tumor of the salivary gland, most commonly the parotid as in this case. Classically presents as a painless mass 1/5 
in a middle-aged adult. Histologic appearance can vary significantly from well-circumscribed, lobulated growth with fibrous septa to infiltrative; papillary, solid, follicular and cystic architectures are common. Watch out for excessive solid growth, necrosis, mitotic 2/5
activity and/or significant cytologic atypia in cases of SC with high-grade transformation. Because of the variable histologic findings, IHC can be essential (esp. when presenting outside of the salivary gland): classically S100+ mammaglobin+ GCDFP-15+ SOX-10+ TTF1- AR-. 3/5
p63 will highlights remaining basal cells if present (can help in ddx with intraductal carcinoma). Mucicarmine/PAS stain the pink/eosinophilic secretions in non-solid areas. SC is defined molecularly by t(12;15) ETV6-NTRK3 rearrangement which is specific in the salivary gland 4/5
but not other sites (PTC, secretory breast carcinoma, Spitz nevi etc.)! 5/5
