HIV-related parotid lymphoepithelial cysts. Immunohistochemistry and 3-D reconstruction of surgical and autopsy material with special reference to formal pathogenesis.
Whether lymphoepithelial cysts in the parotid glands in HIV-infected patients develop from pre-existing salivary gland inclusions in intraparotid lymph nodes or from a lymphoepithelial lesion of salivary parenchyma is unclear. To examine their pathogenesis we performed a histological and immunohistochemical study of salivary specimens from 100 AIDS patients in different disease stages. There is a continuous morphological spectrum of changes within the salivary parenchyma, starting with lymphoid stroma infiltration and evolving to characteristic lymphoepithelial duct lesions with a immunohistochemically proven basal cell proliferation and to fully developed ductal cysts. Involvement of myoepithelial cells-postulated in comparable Sjögren-associated duct lesions-is excluded immunohistochemically. Computer-assisted 3-D reconstructions confirm an association of the cysts with the intralobular duct system. Our study disproves the prevailing hypothesis, which suggests that the lymphoid cell compartment of HIV-associated lymphoepithelial cysts stems from pre-existing intraparotid lymph nodes. The results demonstrate that a secondary lymphatic infiltration of salivary parenchyma provokes a lymphoepithelial lesion of striated ducts with basal cell hyperplasia. The frequent progression to a multifocal cystic lymphoepithelial lesion may be supported by ductal compression through a high degree of lymphofollicular hyperplasia in early disease.
Ihrler
S
S
Institute of Pathology, Ludwig Maximilians University, München, Germany.
Zietz
C
C
Riederer
A
A
Diebold
J
J
Löhrs
U
U
D000328:Adult; D000368:Aged; D002102:Cadaver; D002648:Child; D002675:Child, Preschool; D003560:Cysts / Q000150:complications* / Q000473:pathology / Q000821:virology; D003586:Cytomegalovirus Infections / Q000150:complications; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010305:Parotid Diseases / Q000150:complications* / Q000473:pathology / Q000821:virology