Multiple brown tumours in the maxillofacial region as the initial presentation of primary hyperparathyroidism

We report a rare case of maxillary and mandibular involvement by multiple brown tumours in a patient with primary hyperparathyroidism (PHPT). The patient presented with painless jaw swelling and a pathological fracture of the right humerus. Radiographic evaluation demonstrated multiple osteolytic lesions in the maxilla, mandible and skull. Biochemical investigations revealed severe hypercalcaemia and markedly elevated intact parathyroid hormone (iPTH), and four-dimensional CT confirmed a right inferior parathyroid adenoma. Histopathology, together with negative H3G34W immunohistochemistry, established the diagnosis of brown tumours. Preoperatively, denosumab was administered to control hypercalcaemia, and the patient subsequently underwent targeted parathyroidectomy. Postoperatively, the patient had normalisation of iPTH levels, with regression of the brown tumours over 6 months. This case emphasises the importance of considering PHPT in patients presenting with jaw swelling and highlights the value of a multidisciplinary approach in diagnosis and management.