Papillary oncocytic cystadenoma of a palatal minor salivary gland: A case report

Abstract

Papillary cystadenomas of the salivary gland are uncommon, benign, encapsulated or well-circumscribed, multicystic tumors with intracystic papillations. In a large review, papillary cystadenoma constituted 2% of all minor salivary gland tumors. The present study reports an extremely rare case of a papillary cystadenoma arising from the palate that demonstrated oncocytic features. A 60-year-old man was referred by his dentist to the Second Department of Oral and Maxillofacial Surgery at Osaka Dental University Hospital for the diagnostic evaluation of a mass of the left palate. An incisional biopsy was performed and the microscopic findings were interpreted as consistent with a papillary oncocytic cystadenoma. Therefore, the lesion was excised under general anesthesia. The post-operative course was uneventful and no recurrence had developed 5 years subsequent to surgery.

Keywords: cystadenomas; oncocytic feature; salivary gland.

Figure 1.

Image of the initial presentation, showing a semifirm painless mass in the palate.

Figure 2.

Macroscopic aspect of the cutting surface of the surgical specimen.

Figure 3.

Photomicrograph showing a submucosal adenomatous cystic nodule with papillary intraluminal projections (hematoxylin-eosin stain; original magnification, ×4).

Figure 4.

Cystic papillary projections and the major cyst cavity were lined by bilayer oncocytic columnar epithelium (hematoxylin-eosin stain; original magnification, ×20).

Figure 5.

Positive staining for mitochondria was observed in the oncocytic columnar epithelium (anti-mitochondria antibody stain; original magnification, ×20).