[Show abstract][Hide abstract] ABSTRACT: The aim of our study was to investigate the role of immunopathological processes in the pathogenesis of chronic sclerosing sialadenitis of submandibular glands (Küttner tumor). For this purpose, biopsy specimens from submandibular glands of 22 patients with the histological diagnosis of chronic sclerosing sialadenitis were analyzed. Paraffin-embedded tissues were immunostained for T-lymphocyte subsets (CD3, CD4, CD8), cytotoxic T cells (granzyme B), B cells (CD20, Ki-B3), and macrophages (Ki-M1P). Polymerase chain reaction and capillary electrophoresis were used to detect rearrangements of the T-cell receptor gamma chain and the CDRIII region of the immunoglobulin heavy chain. In all cases, abundant cytotoxic T cells were found, especially in close association with ducts and acini. T-cell receptor gamma chain rearrangements showed a monoclonal pattern in 6 cases (27.3%), an oligoclonal pattern in 8 (36.4%), and a polyclonal pattern in 8 (36.4%). The B-cell reaction was less pronounced and largely restricted to lymph follicles. Molecular analysis of immunoglobulin heavy chain revealed a polyclonal rearrangement in 17 cases (77.3%). In conclusion, there is an intimate relationship between the T-cell-dominated inflammatory infiltrate and acinar and duct cells. This, together with the frequent demonstration of monoclonal and oligoclonal populations of cytotoxic T cells and their histopathological behavior, suggests that chronic sclerosing sialadenitis may be the result of an immune process triggered by intraductal agents.