The prevalence of consolidated salivary deposits in the small ducts of human submandibular glands.

Deposits of apparently solid material were observed in the small salivary ducts in a series of non-diseased submandibular glands obtained from necropsies evenly divided by sex and adult age. The deposits were of granular or laminated structure. They were of mixed staining, the majority being predominantly eosinophilic. A small number of deposits were essentially wholly hematoxylinophilic and some of these were probably calcified. The prevalence of deposits, expressed as the number per unit sectional area, increased steadily with increasing age but was unrelated to sex. An apparently close correlation between intraductal salivary deposits and foci of obstructive adenitis in the same series of glands was shown to be mainly due to the common influence of age. The deposits probably form by precipitation of salivary glycoprotein, possibly because of parenchymal age changes. They may be related to early salivary lithogenesis but the statistical evidence of this study suggests that they are unlikely to be a major factor in the etiology of focal obstructive adenitis.