HIV-Unrelated Benign Lymphoepithelial Cyst of the Parotid Glands Containing Lymphoepithelial Lesion—Like Structures: A Report of 3 Cases

Abstract

Benign lymphoepithelial cyst (BLC) of the salivary gland is uncommon. Among report of these lesions, there were no previous cases of lymphoepithelial lesion (LeL) in human immunodeficiency virus type-1 (HIV-1) unrelated BLC. This study reports 3 cases of HIV-unrelated BLC containing LeL-like structures. Pathologically, 3 lesions were characterized by cuboidal epithelial-lined, cystic spaces, numerous lymphoid follicles, and dense lymphoplasmacytoid infiltrate. Moreover, small lymphocytes invaded the epithelial clusters forming LeL-like structures. Histological findings of 3 lesions resembled marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type. However, staining with CD3, CD5, and CD20 demonstrated the mixed nature of small lymphocytes invading the epithelial clusters (LeLlike structures). Moreover, there were no CD43+ B-lymphocytes in any of the cases. The polytypic nature of B-lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. The 3 cases indicate that HIV-unrelated BLC should be added to the differential diagnosis of MALT-type lymphoma involving the parotid glands.