Non-neoplastic lesions of the salivary glands: New entities and diagnostic problems

SummaryThe histopathology of the salivary glands is a complex and difficult area of diagnostic pathology. In the latest WHO classification there are 40 named neoplasms many of which have variable histological features that can challenge even the most experienced specialist pathologist. In addition, the salivary glands can be affected by a range of non-neoplastic conditions, some of which have only recently been described. These often present clinically like tumours and may have pathological features similar to some of the neoplasms, making diagnosis difficult and errors serious. The purpose of this paper is briefly to review non-neoplastic lesions of the salivary glands and to aid the diagnostic pathologist by describing the key histopathological features of each. The entities covered include: sclerosing polycystic adenosis, cheilitis glandularis, salivary gland hyperplasias, necrotizing sialometaplasia, subacute necrotizing sialadenitis, non-neoplastic oncocytic lesions, salivary gland cysts, lymphoepithelial cysts, polycystic (dysgenetic) disease and HIV associated cystic disease.