Diffuse Large B-Cell Lymphoma Arising in Warthin's Tumor: Case Study and Review of the Literature.

Warthin's tumor is the second most common type of salivary gland tumor. Microscopically, Warthin's tumor displays a proliferative epithelial component and lymphoid stroma. Carcinomas arising from the epithelial component are well known, but malignant transformations of the lymphoid stroma are rare. When they do occur, they are most commonly B-cell type non-Hodgkin lymphomas. A 60-year-old male patient underwent surgical resection of a parotid mass. After superficial parotidectomy, microscopic examination indicated that the tumor was of epithelial components with basaloid and oncocytic columns of cells neighboring lymphoid components. In addition to the lymphoid follicles with distinct germinal centers, there were large, bizarre and extremely atypical neoplastic cells seen in the lymphoid component. Large neoplastic cells were diffusely CD20 and CD30 positive. The patient was diagnosed with "Warthin's tumor and diffuse large B-cell lymphoma with expression of CD30." The histopathologic and clinical features are discussed along with a review of the literature.