Giant parathyroid adenoma diagnosed by brown tumour, a clinical manifestation of primary hyperparathyroidism: A case report.

Brown tumour (BT) is the pathological expression of osteitis fibrosa cystica which is caused due to primary and secondary hyperparathyroidism (HPT). It is a rare benign lesion of skeletal system that usually affects the facial bones, clavicles, ribs, pelvis and extremities. The purpose of this case report is to present the clinical, pathological and radiological findings of BT - rarely seen in adults - originating from the giant parathyroid adenoma and emerging as the first clinical sign of HPT. The patient underwent a successful parathyroidectomy and was discharged on the first postoperative day without any complications. Histopathologically, it was confirmed as parathyroid adenoma. With the increased use of biochemical tests, HPT is diagnosed and treated early and so the frequency of symptomatic HPT due to parathyroid adenoma has decreased in developed countries, but we still sometimes encounter cases of primary hyperparathyroidism (PHPT) occurring as BT. With multidisciplinary preoperative evaluation, surgical resection of bones is refrained from in order to prevent unnecessary morbidity and mortality, unless these osteolytic bone lesions cause a pathological fracture.