Hyperparathyroidism presenting as a large bone tumour. A case report.

A 59-year-old man, who presented to hospital with a large expansile bone tumour over the left elbow and a mass in the right side of the neck, was eventually found to have parathyroid adenoma manifesting clinically as severe hypercalcaemia. Histological examination of a section of the neck mass showed parathyroid adenoma and the bone biopsy specimen revealed a 'brown tumour', consistent with hyperparathyroid bone disease.