LYMPHOEPITHELIAL CYSTS OF SALIVARY-GLANDS - AN IMMUNOHISTOCHEMICAL STUDY OF HIV-RELATED AND HIV-UNRELATED LESIONS

An indolent lesion of the salivary glands that mimics Sjogren syndrome has been repeatedly reported in HIV-infected (HIV+) patients. It is c haracterized by the occurrence, usually in the parotid gland, of varia bly sized lymphoepithelial cysts (LECs), whose origin is still unclear . We have compared the morphological and immunohistochemical features of six cases of LEC in HIV+ patients with those of five cases of LEC i n HIV-negative (HIV-) patients. The results of the study show that LEC s have similar histological and immunohistochemical features in both H IV+ and HIV-patients, and that they may simultaneously affect the sali vary gland parenchyma and the intrasalivary lymph nodes. Furthermore, a diffuse lymphoid infiltrate is invariably observed in the glandular tissue around LECs and it is consistently associated with ectatic chan ges of the striated ducts. These data and the finding of an equivalent proliferation fraction of the epithelial compartment in both LEC and salivary retention cysts, used as controls for this study, are consist ent with the hypothesis that cyst formation is secondary to the obstru ction of salivary ducts by exuberant lymphoid infiltration. Copyright (C) 1998 by W.B. Saunders Company.