Sialolithiasis of minor salivary glands in multiple areas of the lips: Scanning electron microscopy and energy dispersive X-ray spectroscopy analysis

Sialolithiasis of minor salivary gland (SMSG) clinically manifests as an asymptomatic, small, and firm submucosal nodule, and its occurrence in multiple areas is rare. Diagnosing SMSG may be challenging owing to similarities in clinical characteristics with other lesions; misdiagnoses may also occur. In addition to pathological examination, scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDS) analysis can be used to determine the nature of the material. Herein, we report a rare case of a patient with SMSGs in multiple areas of lips, along with SEM-EDS analysis. A 45-year-old female consulted our department with complaints of mild pain and swelling in her lips. Oral examination revealed firm multiple nodules beneath the upper and lower labial mucosa, whereas computed tomography (CT) revealed well-circumscribed multiple hyperdense lesions suggestive of calculi in the upper and lower lips. Following a tentative clinical diagnosis of SMSGs in multiple areas of the lips, three calculi were removed. Histological and SEM-EDS findings supported a final diagnosis of SMSGs. SMSG could be a clinical differential diagnosis of a firm, mobile, and small lip nodule, and SEM-EDS analysis could provide valuable information on the structure and composition of sialoliths. We clinically diagnosed the nodules as SMSGs by careful interpretation of clinical and imaging manifestations. Clinicians should consider SMSG as a clinical differential diagnosis of unknown hard, mobile, and small nodules in lips and buccal mucosa. CT and ultrastructural analysis with SEM and EDS may effectively characterize the sialoliths.