A poorly differentiated salivary carcinoma NOS of the sublingual gland initially presenting as sialolithiasis: implications for early re-assessment in clinical practice.

A 31-year-old woman was referred to the Oral and Maxillofacial Surgery department with a hard swelling in the right floor of the mouth which had the clinical appearance of a salivary calculus. Plain radiography did not demonstrate a radiopacity; however, subsequent ultrasound examination supported this finding. Three months after the initial consultation, while waiting for removal of the calculus, the patient re-presented with mobility of the lower anterior teeth and progressive swelling, prompting repeat orthopantomography and an urgent computed tomography scan of the mandible. These revealed a 27 mm defect within the anterior mandible. Following extensive histopathological examination together with staging investigations and molecular analysis, a diagnosis of T4a, N1, M1 poorly differentiated salivary carcinoma NOS (not otherwise specified) of the sublingual gland was established. Metastatic disease was identified in the lungs, brain and spine, with death occurring ten months after diagnosis. This case highlights the need for careful assessment and heightened awareness of rare salivary gland pathologies particularly when symptoms progress despite initially unremarkable investigations.