Warthin's Tumor: Electron Microscopic Studies

Abstract

PAPILLARY cystadenoma lymphomatosum, a benign neoplasm of the human parotid gland, was first recognized in 1895 by Hildebrand¹ and was accurately described in 1910 by Albrecht and Arzt.² This tumor acquired its eponymic designation in 1929, when it was described in the American literature by Warthin.³ Warthin's tumor is thought to arise from salivary gland structures incorporated in lymph nodes adjacent to or embedded in the parotid gland.^4,5 Azzopardi and Hou⁴ have demonstrated direct histological transition from normal ducts to tumor epithelium. Smith⁵ considers Warthin's tumor to be the result of metaplastic and neoplastic alteration of salivary gland ductal epithelium accompanied by an increase in lymphoid tissue. In the light microscope, Warthin's tumor is seen to be made up of blunt, papillomatous processes, which consist of masses of lymphoid cells covered by a layer of pseudostratified epithelium.⁶ These processes project into cystic spaces