Oncocytic Papillary Cystadenoma, an Unusual Variant Presenting as a Laryngeal Ventricular Cyst.

Cystadenoma arising from the larynx is a rare benign minor salivary gland tumor that can show mucinous or papillary morphology. The epithelial lining of the salivary gland tumor can present with oncocytic features, which is attributed to an increased number of mitochondria. We present a rare case of oncocytic papillary cystadenoma (OPC) of the larynx which has a combination of these features. The WHO defines OPC tumors as entities which closely resemble Warthin tumor, but lack its classic lymphoid component. The immunohistochemical profile and molecular genetic features are largely unknown. We present an 84-year-old female, former smoker, who presented with progressive dysphonia, dysphagia, and shortness of breath. Laryngoscopy revealed a large, smooth mass originating from the ventricle of the right vocal fold. Subsequent biopsy demonstrated cyst wall fragments lined by a bilayer of large columnar to cuboidal oncocytic cells that had granular eosinophilic cytoplasm, round to oval nuclei with finely dispersed chromatin, and small but distinct nucleoli. The surrounding stroma was slightly fibrotic with scant lymphoid elements. No nuclear pleomorphism, increased mitosis, or necrosis was identified. In the larynx, benign salivary gland tumors are rare and less frequent than malignant neoplasms. Awareness of rare benign entities like OPC help ensure proper management and aid in avoiding unnecessary therapy.