Minor salivary gland calculi. A clinicopathologic study of forty-seven new cases.

An analysis of forty-seven previously unreported cases of minor salivary gland calculi revealed that they were usually solitary, firm, freely movable, small masses. Also, we noted that these calculi exhibited a striking predilection for the upper lip and buccal mucosa of adults. The organic matrix of all calculi was similar; however, the amount of mineralized material was variable. A variety of types of epithelial metaplasia was noted in the pericalcular ducts, with the most common type being squamous-cell metaplasia. Chronic periductal and lobular inflammation in addition to duct ectasia were common findings. The cause of minor salivary gland calculi is not known; however, local factors, such as duct morphology or biochemical alterations, or both, may be involved.