Aneurysmal bone cyst of the distal thumb phalanx. A case report and review of the literature.

Although aneurysmal bone cysts are a well-known, well described clinical entity, their presence in small bones of the hand are not a common occurrence. Only 13 previous cases involving the bones of the hand have been reported in the English literature. Of these 13, only seven involved the phalanges and no previous case has been described involving the distal phalanx of the thumb. Because these lesions may demonstrate aggressive local biologic behavior, when the diagnosis of aneurysmal bone cyst of the small bones of the hand is considered, prompt diagnostic and therapeutic intervention should be performed. Early recognition and management of this lesion is essential to prevent amputation.