Pathogenesis of Warthin's tumors.

INTRODUCTION: Warthin's tumor, also known as papillary cystadenoma lymphomatosum, monomorphic adenoma, or adenolymphoma, is a benign cystic tumor of the salivary glands containing abundant lymphocytes and lymph node-like stroma. It is named after the pathologist Aldred Scott Warthin, who described two cases in 1929.

OBJECTIVE: The aim of this study is to analyze the pathogenesis of Warthin's tumor.

METHODS: A total of 15 patients with Warthin's tumor were studied. Hematoxylin and eosin stains, which have been used for at least a century and are still essential for recognizing various tissue types and the morphologic changes for cancer diagnosis, were used. Warthin's tumor was evaluated for the expression of MGMT, CD3, HSP90AA1, MMP-1, Bcl-2, CD79A, IgG, Ki-67, p53, IgM, OPN, S100, myeloperoxidase, and VEGF by immunohistochemistry.

RESULTS: Immunohistochemical staining confirmed that the immune cells within the follicles of Warthin's tumor were positive for MGMT (10.0 ± 0.34%), Ki-67 (13.3 ± 0.45%), Bcl-2 (42.6 ± 8.33), and p53 (11.6 ± 2.3). The immune cells associated with CD3 were present at the stroma of residual cells (47.3 ± 3.89); however, they were not present in the epithelium cell layers. B cells (CD79A) consistent with germinal centers were present within the immune cells and formed follicles (43.2 ± 13.5%).

CONCLUSIONS: Histopathological analysis of the stroma and parenchyma revealed balanced distribution of epithelial and stromal component. Epithelial component of the Warthin's tumor is the trigger for the tumor process. This study indicates that the Warthin tumor is a consequence of inflammatory etiology.