Summary

Synchronous tumours of different histological types involving the salivary gland are very rare. There have been cases reported in the literature of such tumours occurring in the parotid gland. A 52-year-old man presented with a 4-year history of gradually increasing painless swelling in the right submandibular region. The ultrasound scan of the neck showed features suggestive of a submandibular sialadenitis. The right submandibular gland was then surgically excised and sent for histopathological examination. The features showed a unique dual pathology of the submandibular gland, that is, a plasmacytoma and a pleomorphic adenoma. Such a synchronous double pathology involving the submandibular gland has not been reported in the literature. A review of the literature suggests a good prognosis for the extramedullary plasmacytoma, provided multiple myeloma is ruled out. In 18 months of follow-up, the patient has been asymptomatic with a negative myeloma workup.