Parathyroid carcinoma presenting with a brown tumour of the mandible in a young man.

A 27-year-old man presented to his dentist with a swelling in his lower jaw. Histology revealed this to be a brown tumour associated with primary hyperparathyroidism and severe but asymptomatic hypercalcaemia. A large parathyroid adenoma was removed and the serum calcium fell to normal. Hypercalcaemia recurred and re-exploration of the neck revealed parathyroid metastases in cervical lymph nodes. A modified radical neck dissection was performed and he has remained normocalcaemic on Vitamin D analogues for 2 years. Bone disease of the mandible is a very rare presentation of primary hyperparathyroidism. The diagnosis of parathyroid malignancy is often difficult histologically, and the optimum treatment is uncertain.