Papillary oncocytic cystadenoma of the parotid glands: a report of 2 cases with varied cytologic features.

Background: Papillary cystadenoma is a rare salivary gland neoplasm, and oncocytic change can be focal or marked. Papillary oncocytic cystadenoma has been reported mainly in the minor salivary glands and occasionally in the parotid glands. The cytologic features vary.

Methods: A 26-year-old female presented with a 2.4-cm, cystic right parotid gland mass present for 4 months. Fine needle aspiration (FNA) showed cellular smears with sheets of oncocytic cells and some with micropapillary architecture. The diagnosis ofa neoplasm was rendered and excisional biopsy recommended. Oncocytic neoplasm was diagnosed during intraoperative consultation, and final surgical histology showed a unilocular, cystic, oncocytic neoplasm with variable papillary projections. A 52-year-old male presented with a 1.5-cm, cystic left parotid mass enlarging for the past few months. FNA showed less cellular smears with extensive necrotic debris and a few large sheets of epithelial cells with vague papillary architecture. Oncocytic neoplasm was diagnosed during intraoperative consultation, and final surgical histology showed a unilocular cystic lesion with multiple papillary fronds lined with oncocytic cells and focal metaplastic squamous cells.

Conclusions: Papillary cystadenoma is rare in the parotid glands, and cytologic features may vary. Warthin's tumor, oncocytoma, intraductal papilloma and acinic cell carcinoma may arise in the differential diagnosis. In cases with extensive necrotic debris and metaplastic squamous cells, branchial cyst and cystic metastatic squamous carcinoma may also need to be considered.