The Migrating Sialolith: a Case Report

Abstract

Over 80% of sialoliths form in the submandibular glands. Well-recognized complications include blockage or narrowing of salivary ducts leading to pain, edema, and infection. Less commonly, fistulas may develop into the oral cavity and very rarely, sialoliths may migrate to the skin’s surface. Our literature review revealed only five reported cases of migrating sialoliths with two reporting stones migrating down the neck prior to eroding through the skin. An 89-year-old woman with a history of chronic sialolithiasis in the right submandibular gland with a sialolith documented on CT 2 years prior, presented with a rapidly growing skin lesion overlying her right sternocleidomastoid in level three. Repeat CT showed a similar sized sialolith underneath the skin lesion and atrophy of the right submandibular gland. This is a rare case of a sialolith eroding through the submandibular gland, tracking down the neck and through the skin. We propose the mechanism of this complication is that the stone causes inflammation and scarring within the gland obstructing Wharton’s duct leading to increased pressure from salivary back flow. The gland becomes ischemic and the stone is slowly forced through the gland. We believe that the stone then migrates along the investing fascia of the submandibular gland and sternocleidomastoid muscle. This paper is the first to propose a mechanism for this complication and is one of the few cases with pre- and post-migratory imaging. This case helps provide further evidence to support appropriate treatment and follow-up on patients with chronic sialolithiasis.