Maxillary brown tumour: unusual presentation of parathyroid carcinoma
This is a report of a maxillary brown tumour caused by primary hyperparathyroidism (HPT) secondary to parathyroid carcinoma. A 62-year-old man presented with a large swelling in the right maxilla, which caused right-sided nasal obstruction, intermittent bleeding and diplopia. A computed tomography scan demonstrated an expansible, destructive soft tissue mass centred on the right ethmoid sinus, extending from the maxilla to the orbital floor. Histology showed a central giant cell granuloma of bone, thought to be a brown tumour of HPT and this was supported by serum calcium of 3.0 mmol/l and serum parathyroid hormone of 880 ng/l (normal 7 to 40 ng/l). Parathyroid imaging was consistent with a left lower parathyroid adenoma. The patient underwent removal of the parathyroid gland, left hemithyroidectomy and central node dissection. Histology confirmed parathyroid carcinoma. Surgical removal of the brown tumour was offered but declined. The symptoms improved and the maxillary swelling gradually reduced in size. The management of brown tumours is controversial, but a pragmatic approach is essential to a successful outcome. The general consensus seems to be adequate treatment of the HPT and surgical excision of the brown tumour only if the mass effect of the lesion is troublesome.
Keywords: parathyroid carcinoma, brown tumour, primary hyperparathyroidism