Role of microliths in the aetiology of chronic submandibular sialadenitis: a clinicopathological investigation of 154 cases

Aims: Confusion about the aetiology and pathogenesis of chronic submandibular sialadenitis led to the present investigation of 154 cases in which many clinical and histological features were analysed. Methods and results: By far the greatest number of histological factors, namely liths, atrophy, fibrosis, parenchymal inflammation, lymphoid germinal centres, mucous and ciliary metaplasia, salivary extravasation and glycosaminoglycan accumulation was related to the degree of inflammation, which appears to be of the greatest importance in the aetiology and pathogenesis. Inflammation, atrophy and fibrosis were related to duration of symptoms, which supports the concept of a chronological progression through increasingly severe histological changes. Conclusions: Inflammation possibly arises from ascending infection in a normal grand and exerts an obstructive and destructive effect on the parenchyma with the development of the related histological changes and a vicious circle involving further ascending infection. Normal glands contain microliths that possibly by localized obstruction cause atrophic foci that are reservoirs for ascending infection. Microliths and liths were unrelated: microliths were related to age as in normal glands whereas liths were related to duration of symptoms and appeared to be secondary to the sialadenitis. Many glands showed minimal changes, which raises the possibility of conservative treatment.