[Radiation-induced sialadenitis. Stage classification and immunohistology].

The course of radiation-induced sialadenitis in 58 cases in the salivary gland registry (Institute for Pathology of the University of Hamburg 1965-1987) was subjected to pathohistological and immunohistochemical analysis. The pathohistological changes may be classified by severity into 3 stages. Stage I is characterized by mild inflammatory interstitial changes and moderate atrophy of individual glandular acini. In Stage II there is an increase in inflammatory infiltrate in connection with fibrotic changes in the interstitium and epithelial metaplasia in the ductal system. In stage III we find cirrhotic parenchymal alteration with clear inflammatory activity and an almost complete parenchymal atrophy. Immunohistochemically, the markers for secretory gland function (immunoglobulin A, secretory components, lysozyme, lactoferrin) show an increased reaction in the ductal system during stages II and III, while the amylase reaction decreases or is absent, as would be expected with increasing parenchymal atrophy.