Aneurysmal bone cyst of the metatarsal: A case report.

An aneurysmal bone cyst (ABC) is a rare, non-neoplastic, destructive, hemorrhagic and expansile lesion accounting for 1% of all bone tumors. This type of lesion predominantly affects long bones and vertebrae. ABC of the metatarsal is rare and only a few cases have been reported in the literature to date. The present study reports a rare case of ABC of the third metatarsal occurring in a 27-year-old male patient, who presented with repeated foot swelling that had lasted for ~1 year. Other clinical manifestations included limping, multiple lumps (defined as masses on or below the skin, as detected by imageological diagnosis) and progressively increasing local pain in his right foot. Magnetic resonance imaging of the right metatarsal revealed a segmented, expansile, multiseptated lesion with fluid-fluid levels. An en bloc resection was performed and the defect was replaced with a tricortical iliac autograft. Pathological analysis of the resected tissue suggested ABC. The present study aims to describe a case of ABC of the metatarsal, a condition that often poses a diagnostic challenge, and to underline the importance of radiological and histological examinations for the accuracy of that diagnosis.