Papillary cystic oncocytoma and Warthin's tumor of the parotid gland

A 69-year-old white female had a left superficial parotidectomy for a papillary cystic oncocytoma. The histologic appearance was identical to Warthin's tumor except that it lacked a lymphoid component. This case suggests that the general morphology of a Warthin's tumor does not depend on the presence of lymphoid tissue or association with an intra-parotid lymph node. We reviewed 50 patients with Warthin's tumor to investigate the histogenesis of the lesion. We found that most Warthin's tumors (86%) appeared to be within lymph nodes, as indicated by the presence of a lymph node capsule or sinuses. The anatomy of intra-parotid lymph nodes in glands containing Warthin's tumors has been compared with that found in 11 parotid glands containing mucoepidermoid carcinomas. So-called heterotopic ductal inclusions may actually represent the normal intimate relationship of parotid gland to intra-parotid lymph nodes.