Incidental finding of sialolithiasis in the sublingual gland: a diagnostic dilemma

Sialolithiasis is a common condition and occurs mainly in the submandibular gland (80–90%) and, to a lesser extent, in the parotid gland (5–20%). The incidence of stones in the sublingual gland is much lower, the incidence varying from 0–6.4%.^1,2 The figure of 6.4% may represent misdiagnosis of stones in the anterior portion of Wharton's duct.

Symptoms associated with sialolithiasis may include swelling and pain of the involved gland, especially during mealtimes. The symptoms tend to subside and recur on a regular basis. Stones, however, may be completely asymptomatic and present as incidental findings on radiographic examination. We describe a patient with multiple sialoliths in the sublingual gland who was initially thought to have multiple submandibular duct calculi.

A 35-year-old female was referred to the Oral and Maxillofacial Surgery Department with symptoms suggestive of TMJ dysfunction syndrome. An incidental radio-opaque lesion was seen on the orthopantomogram and hence a standard lower occlusal was taken (Figure 1). This revealed multiple stones in the floor of the mouth. The patient was completely asymptomatic and clinical examination was unremarkable. Both Wharton's ducts were patent with expression of clear salivary flow on gentle manipulation of the submandibular glands. The provisional clinical diagnosis at this stage was multiple sialoliths in the right submandibular gland and duct. Sialography was attempted but was not tolerated. The floor of the mouth was therefore explored under local anaesthesia but, owing to per-operative problems, no stones were recovered at the time. Further exploration was carried out under general anaesthesia at which time multiple sialoliths were found in the sublingual salivary gland. The right sublingual salivary gland, together with the five stones, the largest measuring 7x6x4 mm, were removed by an intra-oral approach (Figure 2). Macroscopic histology sections revealed multiple calculi whilst microscopic views showed chronic sialoadenitis with focal areas of acinar atrophy and duct dilatation (Figure 3). Post-operative recovery was uneventful.