 | The ankle radiograph of a 9 year old girl with pain and limp for a few months. An osteolytic lesion is seen in the distal tibial metaphysis. In this case, the osteolytic lesion progressed spontaneously, as noted in the next image. |
 | After open biopsy, the diagnosis of an active aneurysmal bone cyst was made. The treatment was curettage plus the use of a sliding cortical antogenous bone graft into the defect, held in place with two screws. |
 | The lesion progressed rapidly and destroyed most of the autogenous bone grafts. |
 | Massive recurrence developed, which almost completely destroyed the bone grafts, and progressed osteolysis. At this point many physicians mistakenly thought that the rapid destruction of the bone grafts and progression of the lesion indicated that the lesion was malignant, and suggested that the diagnosis could be telangiectatic osteosarcoma when the x-rays demostrated osteolysis. |
 | For unknown reasons, her leg was immobilized in a long cast for several months, which led to deformity with varus and equinus positions of the foot and ankle |
 | Reconstruction surgery was required to achieve a reasonable position of the tibia and ankle. Bone grafting of the residual cystic lesion was also done. There was no pathological evidence of an active aneurysmal bone cyst, now two years later. The patient is doing reasonably well, but with disability. She may need further treatment. |