Sialolith of a minor salivary gland.

Sialoliths represent non-neoplastic calcified masses found in intraor extra-glandular salivary ducts.1 The submandibular gland is affected in 80-92% of cases, the parotid gland in 6-19%, and sublingual or accessory/minor salivary glands in 2%.2 Most require surgical removal, although spontaneous ejection of the calculus can occur. In the case that is illustrated on the cover of this issue of the JCP , a 68-year-old man presented with a several month history of an asymptomatic mass in his right upper lip. His past medical history was significant for a squamous cell carcinoma on his chest a year earlier, mild hypertension, osteoarthritis and previous alcohol and tobacco abuse. On examination, the lesion was hard, easily palpated and best visualized on the mucosal surface of the lip. The differential diagnosis included a mucocele, a mixed tumor, or a cyst. An excisional biopsy was completed. Histopathologically, within the submucosa there was a well-demarcated nodule surrounded by epithelium exhibiting connection to a minor salivary gland duct (Figure 1). In the center of the nodule was an amorphous and homogenous aggregate of bluish material with focal calcium deposition. The nodule itself included a cuticle-like periphery comprised of compact eosinophilic material (Figures 2 and 3) with an adjacent rim of von Kossa-positive calcium (Figure 4). The stroma exhibited inflamed minor salivary glands, indicating sialadenitis (Figure 5). The salivary duct demonstrated dilatation and inspissated inflammatory cells with surrounding lymphocytes, plasma cells and eosinophils (Figure 6). The duct wall showed evidence of squamous and mucinous metaplasia (Figure 7). Minor or accessory salivary glands are found in the lips, tongue, cheeks, floor of the mouth, Fig. 1. The submucosa holds a well-demarcated oval mass surrounded by an epithelial lining and diffuse stromal inflammation.