Aneursymal bone cyst of the proximal phalanx of the thumb in a child.

Aneursymal Bone Cysts (ABCs) involving the hand are a rare occurrence. We report a case of an ABC of the proximal phalanx of the thumb in a boy which was treated successfully with curettage and autologous bone grafting. When the diagnosis of ABC of the small bones of the hand is entertained, prompt therapeutic intervention is indicated because of the potential for aggressive local behaviour. In the paediatric patient, simple surgery to preserve the growth plate is recommended.