Third metatarsal brown tumor with secondary hyperparathyroidism: an atypical localization.

Brown tumors represent the terminal stage of the remodeling process during primary or secondary hyperparathyroidism. We report the first case of brown tumor on the third metatarsal associated with secondary hyperparathyroidism caused by vitamin D deficiency. Radiography showed an expansile tissue mass in the third metatarsal bone. The diagnosis was suggested by the clinical history and was confirmed by biochemical, radiologic, and histopathologic determinations. After intravenous therapy with calcidiol, 1g/d, her symptoms were relieved. The brown tumor showed regression and ossification during the 3 months after therapy.