Salivary duct carcinoma.

Twelve cases of salivary duct carcinoma were examined clinically, pathologically and by flow cytometry to quantify their histological features as well as attempt to identify factors predictive of patient outcome. All of the tumours arose in the parotid gland. Eight of the twelve patients were male. Four patients died of disease (median survival 12.5 months); three are alive with disease; and five are alive with no evidence of disease (mean follow-up of 50 months). Two tumours arose in a pre-existing pleomorphic adenoma. Positive lymph nodes were present in eight of ten patients sampled; patients with two or more positive lymph nodes tended to die of their disease or be alive with metastases. Comedo necrosis, perineural invasion and vascular invasion were common findings by light microscopy. Ten of the twelve tumours were aneuploid. Neither clinical stage, tumour size, aneuploidy nor histological features correlated with patient outcome. This study confirms the aggressive nature of salivary duct carcinoma.