Fine-needle aspiration cytology of salivary duct carcinoma

Salivary duct carcinoma (SDC) is an extremely rare and highly aggressive primary epithelial neoplasm of the salivary glands associated with increased tendency for lymph node and vascular metastases. Histologically, this lesion resembles intraductal cribriform and comedo carcinoma of the breast. Fine-needle aspiration (FNA) cytology of SDC in two patients with parotid masses (ages 65 and 67) is presented. The aspirates were sparsely to richly cellular and contained predominantly broad flat and branching sheets of large polygonal epithelial cells with abundant eosinophilic cytoplasm, round to oval nuclei, finely granular chromatin and prominent nucleoli. Few sheets showed cribriforming and papillary configuration. The cytologic differential diagnosis included oncocytoma, acinic cell carcinoma, muco-epidermoid carcinoma, and metastatic adenocarcinoma. To the best of our knowledge, this is the first report to describe a spectrum of cytologic features that may allow a specific FNA diagnosis of SDC. Preoperative diagnosis of this neoplasm may warrant a more extensive radiologic workup and therapy including radical surgery and neck dissection followed by radiation therapy.