Maxillary brown tumour as the initial presentation of primary hyperparathyroidism.

Brown tumours are rare skeletal manifestations of primary hyperparathyroidism (PHPT). They mimic giant cell-rich lesions and are usually found in the mandible, ribs, pelvis or long bones. Maxillary involvement is exceptionally rare. In this report, a middle-aged woman presented with right cheek swelling due to an expansile maxillary lesion initially diagnosed as a maxillary giant cell tumour, with surgery planned on that basis. Further evaluation revealed multiple skeletal lesions, markedly raised parathyroid hormone and a parathyroid adenoma. She underwent a successful parathyroid adenoma excision after which her biochemical abnormalities were resolved. The maxillary lesion was diagnosed as a brown tumour secondary to PHPT. This case highlights how maxillary brown tumours may be the first manifestation of PHPT. Early recognition through biochemical testing is crucial to avoid unnecessary aggressive surgery as definitive treatment lies in parathyroidectomy.