Brown tumors of the jaws: A retrospective study

Brown tumors are a rare non-neoplastic bone lesion resulting from an abnormal bone metabolism such as the increase of osteoclastic activity and fibroblastic proliferation. Usually, they are found in severe and advanced forms of hyperparathyroidism (HPT), which is a common endocrine disorder characterized by hypercalcemia and the elevation of parathyroid hormone serum level. Three types of hyperparathyroidism may be associated with those brown lesions: ? A primary HPT characterized by an excessive parathyroid hormone (PTH) production and hypercalcemia (mostly due to a parathyroid adenoma); ? A secondary HPT: usually caused by vitamin D deficiency, malabsorption or hypercalciuria; ? Or a tertiary HPT, which develops from secondary hyperparathyroidism and evolves into a more severe circumstance with autonomous PTH secretion. The diagnosis of Brown tumors actually depends on the presence of one of the hyperparathyroidism described above, since histologically the aspect of Brown tumors cannot be distinguished from giant cell lesions features. Therefore, the diagnosis of a Brown tumor is reported when the pathology reveals a “giant cell lesion” and the medical investigation report hyperparathyroidism. The location of Brown tumors is often polyostotic but the involvement of the jaws is unusual since they are more commonly localized along long bones such as the pelvis, ribs, and clavicles. The aim of our work was to study the various anatomo-clinical, radiological, therapeutic, and evolutionary aspects of maxillary brown tumors ( representing less than 2% of Brown tumors).