Oncocytic papillary cystadenoma of the larynx: comparative study of ten cases and review of the literature

Introduction A vast increase in knowledge of numerous aspects of malignant salivary gland tumours has emerged during the last decade and, for several reasons, this has not been the case in benign epithelial salivary gland tumours. We have performed a literature review to investigate whether an accurate histological diagnosis of the 11 different types of benign epithelial salivary gland tumours is correlated to any differences in their clinical behaviour. Methods A search was performed for histological classifications, recurrence rates and risks for malignant transformation, treatment modalities, and prognosis of these tumours. The search was performed primarily through PubMed, Google Scholar, and all versions of WHO classifications since 1972, as well as numerous textbooks on salivary gland tumours/head and neck/pathology/oncology. A large number of archival salivary tumours were also reviewed histologically. Results Pleomorphic adenomas carry a considerable risk (5–15%) for malignant transformation but, albeit to a much lesser degree, so do basal cell adenomas and Warthin tumours, while the other eight types virtually never develop into malignancy. Pleomorphic adenoma has a rather high risk for recurrence while recurrence occurs only occasionally in sialadenoma papilliferum, oncocytoma, canalicular adenoma, myoepithelioma and the membranous type of basal cell adenoma. Papillomas, lymphadenoma, sebaceous adenoma, cystadenoma, basal cell adenoma (solid, trabecular and tubular subtypes) very rarely, if ever, recur. Conclusions A correct histopathological diagnosis of these tumours is necessary due to (1) preventing confusion with malignant salivary gland tumours; (2) only one (pleomorphic adenoma) has a considerable risk for malignant transformation, but all four histological types of basal cell adenoma can occasionally develop into malignancy, as does Warthin tumour; (3) sialadenoma papilliferum, oncocytoma, canalicular adenoma, myoepithelioma and Warthin tumour only occasionally recur; while (4) intraductal and inverted papilloma, lymphadenoma, sebaceous adenoma, cystadenoma, basal cell adenoma (apart from the membranous type) virtually never recur. No biomarker was found to be relevant for predicting recurrence or potential malignant development. Guidelines for appropriate treatment strategies are given. Electronic Supplementary material The online version of this article (10.1007/s12325-019-01007-3) contains supplementary material, which is available to authorized users.

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.

Clinically significant cysts in the region of the larynx are uncommon. In this study, 20 cases were recovered for the period 1969-1983. There were eight males and 12 females whose ages ranged from 28-76 years and whose most common symptom combinations were hoarseness (9), local foreign body sensation (5), and pain (4). Laryngoscopic examination revealed cystic lesions 0.5-3.0 cm. in diameter, all localized to the supraglottis with half in the vallecula . Histologically, 17 cysts were closely associated with tonsillar lymphoid tissue. Nine cysts, having squamous lined crypt-like structures and abundant follicular lymphoid tissue, were designated "tonsillar cysts." Eight cysts had a prominent epithelial component and focal follicular lymphoid aggregates. Three cysts were unassociated with lymphoid tissue. Two of these, located in the ventricles of elderly patients, were oncocytic cysts. Both showed oncocytic changes on the surface mucosa and in adjacent salivary gland tissue. In one case, a biopsy of the contralateral ventricle demonstrated oncocytic metaplasia. Treatment in all cases was by surgical excision. Follow-up on 13 patients ranging from three months to 9 years revealed one recurrence of an oncocytic cyst one year after initial removal. We conclude that follicular lymphoid tissue is present in most laryngeal cysts and may play some pathogenetic role in their formation. Furthermore, oncocytic cysts are different from other laryngeal cysts, having a characteristic location, age group, field effect, and recurrence rate.