Differential diagnosis of brown tumor vs. cystic osteitis by arteriography and computed tomography.

An expansile lytic lesion of bone can be either a brown tumor or a cyst when the patient has hyperparathyroidism. If weight-bearing bones are involved, the diagnosis must be made prior to parathyroidectomy in order to avert a possible pathological fracture. In the authors' patient, arteriography and computed tomography both demonstrated that the lesion in question was a brown tumor, which is hypervascular and clearly separable from a fluid-filled cyst; however, CT has the advantage of being a noninvasive procedure.