Uncommon presentation of brown tumours revealing hyperparathyroidism: Three case reports.

Brown tumours (BTs) are focal bone lesions encountered in patients with uncontrolled hyperparathyroidism (HPT). They are due to a proliferation of multinucleated giant cells in osteolytic lesions. Because of early screening of bone metabolism disorders, BTs are rare bone manifestations. More importantly, they scarcely reveal the disease. We demonstrate through these two cases reports unusual locations of BT complicating the course of HPT due to parathyroid hyperplasia.