Oxyphil cell carcinoma of the parathyroid: a rare cause of hyperparathyroidism

Oxyphil carcinoma of the parathyroid is an extremely rare tumour, only two previous patients having been reported. We report a 55-year-old woman with this condition, who presented with a picture of hyperparathyroidism, including hypercalcaemia, hypercalciuria, hypophosphataemia, increased alkaline phosphatase, and bony lesions. Biopsy of a bone lesion was consistent with brown tumour. Fine needle aspiration cytology and subsequent operative histology of the parathyroid lesion showed an oxyphil cell tumour with malignant characteristics. Following excision, the patient made a good recovery, complicated only by postoperative hypocalcaemia.