Salivary duct carcinoma: cytologic characteristics and application of androgen receptor immunostaining for diagnosis.

BACKGROUND: Although there have been several reports of cytologic features for salivary duct carcinoma (SDC), it still can be difficult to diagnose patients with these tumor accurately at the time of fine-needle aspiration (FNA). Review of the literature indicates that, immunohistochemically, SDC expresses androgen receptor (AR) in the majority of patients. The authors investigated the cytologic characteristics and utility of AR immunostaining on cytologic smears for the diagnosis of patients with SDC.
METHODS: FNA and imprint smears from four patients with SDC were stained with Papanicolaou and periodic acid-Schiff (PAS). Immunostaining for AR on paraffin sections and imprint smears of SDC was performed, including 51 benign and other malignant salivary gland tumors.
RESULTS: The smears were cellular and contained three-dimensional clusters, flat sheets, and scattered epithelial cells with necrotic backgrounds. A cribriform architectural pattern was noted in many of the tumor sheets. The tumor cells were large polygonal, spindle, and round to oval, and had abundant, finely granular, or vacuolated cytoplasm. Intracytoplasmic vacuoles were PAS negative. The nuclei were hyperchromatic, medium to large in size, round to oval in shape, and often had prominent nucleoli. All SDC tumors expressed AR. Two patients with carcinoma in (pleomorphic adenoma) showed a focal, comedo carcinoma pattern in which AR positive nuclei were observed. Other salivary gland tumors were completely negative for AR.
CONCLUSIONS: The cytologic features of high-grade adenocarcinoma with a variety of cell morphologies, flat sheets of tumor cells with a cribriform pattern, and necrotic backgrounds are characteristic findings in patients with SDC. Immunostaining for AR on cytologic smears is useful for the diagnosis of these patients. Copyright 2001 American Cancer Society.