Brown Tumors (Osteitis Fibrosa Cystica): Causes, Diagnosis, and Treatment

Brown tumors are benign, lytic bone lesions resulting from severe hyperparathyroidism (usually primary). Excess parathyroid hormone (PTH) drives osteoclast‑mediated bone resorption, replacing normal bone with fibrous tissue, hemorrhage, and multinucleated giant cells—giving a brown appearance.

Common sites: jaws, long bones, ribs, pelvis.

Clinical features: localized bone pain, swelling, tenderness; pathologic fractures and deformities in advanced cases.

Diagnosis: imaging (X‑ray, CT, MRI showing expansile lytic lesions) plus biochemical confirmation of hypercalcemia and elevated PTH.

Treatment: primary is surgical removal of the overactive parathyroid gland(s) (parathyroidectomy), which usually leads to lesion regression. Adjunctive measures include calcium‑lowering medications and, for symptomatic fractures/deformities, surgical curettage or bone grafting.