The patient proceeded to ultrasound guided core biopsy.
Histopathology
MICROSCOPIC DESCRIPTION: The core biopsy shows parotid parenchyma. There is invasive carcinoma, surrounded by fibrous stroma. The tumour forms trabeculae and nests. No glands are noted. The tumour cells are focally crushed. They have enlarged nuclei, conspicuous nucleoli and moderate amounts of pale eosinophilic cytoplasm. There is no obvious keratinisation. No mucous cells are seen. There is no comedo-type necrosis. No evidence of lymphovascular or perineural invasion is identified. The tumour cells are CK7, BER-EP4, GCDFP-15 and androgen receptor positive. They are c-kit, DOG1, PSA, PSAP, p40 and p63 negative. The immunoprofile is consistent with salivary duct carcinoma.
DIAGNOSIS: Parotid core biopsy: Features consistent with salivary duct carcinoma.