Aneurysmal bone cyst arising from a fibrous metaphyseal defect in a toddler.

Abstract

This is a case of aneurysmal bone cyst arising from a fibrous metaphyseal defect of the proximal tibia in a toddler. A 32-month-old girl presented with physiologic bowing with a small metaphyseal defect at the medial aspect of the left proximal tibia. A large aneurysmal bone cyst, occupying almost the entire metaphysis of the proximal tibia, evolved from this lesion during the following 1 year 3 months. The lesion healed uneventfully after curettage and bone grafting. This case emphasizes the importance of regular followups to observe the clinical course of a fibrous metaphyseal defect during childhood.