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 pa tients with these tumor accurately at the time of fine-needle aspiration (F NA). Review of the literature indicates that, immunohistochemically, SDC ex presses androgen receptor (AR) in the majority of patients. The authors inv estigated 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 wi th Papanicolaou and periodic acid-Schiff (PAS). Immunostaining for AR on pa raffin sections and imprint smears of SDC was performed, including 51 benig n 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 c ribriform architectural pattern was noted in many of the tumor sheets. The tumor cells were large polygonal, spindle, and round to oval, and had abund ant, finely granular, or vacuolated cytoplasm. Intracytoplasmic vacuoles we re PAS negative. The nuclei were hyperchromatic, medium to large in size, r ound to oval in shape, and often had prominent nucleoli. All SDC tumors exp ressed AR. Two patients with carcinoma in (pleomorphic adenoma) showed a fo cal, comedo carcinoma pattern in which AR positive nuclei were observed. Ot her salivary gland tumors were completely negative for AR. CONCLUSIONS. The cytologic features of high-grade adenocarcinoma with a var iety of cell morphologies, flat sheets of tumor cells with a cribriform pat tern, and necrotic backgrounds are characteristic findings in patients with SDC. Immunostaining for AR on cytologic smears is useful for the diagnosis of these patients. (C) 2001 American Cancer Society.