| Images of Musculoskeletal Oncology |
| Aneurysmal Bone Cyst - Primary |
| An 8 year old girl presents with right ankle pain, slight tenderness, and limp for two months. |
| An osteolytic lesion is noted in her right distal tibia metaphysis, with slight widening of the medullary canal and thinning of the cortex. |
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| The CT scan reveals that the central portion of the lesion is osteolytic, with some reactive bone around it. The differential diagnosis includes aneurysmal bone cyst and simple bone cyst. Giant Cell Tumor would be unlikely, because the lesion does not include any portion of the epiphysis, and the patient is too young. |
 | The patient was treated by open biopsy, yielding reddish friable soft tissue within the metaphysis, demonstrating vascular tissue with benign appearing fibrous tissue, new bone, and occasional multinucleated giant cells. The diagnosis of an active primary aneurysmal bone cyst was made. Some tissue suggests that lining tissue is also seen, showing the pathologic difficulties seen in separating a simple bone cyst from an aneurysmal bone cyst. |
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| The lesion was thoroughly curetted, and the resultant cavity filled with crushed allograft cortical and cancellous bone chips. |
 | The patient did well postoperatively, but developed recurrent pain and limp at two years post op, likely due to recurrent aneurysmal bone cyst. |
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 | Demonstrates the radiographic appearance after recurretage and repacking with crushed allografts. |
 | Five years after being first seen, she is asymptomatic and functions normally. The allografts have been completely incorporated without further recurrence. |
 | This clinical photograph demonstrates an ankle close to normal, with a surgical scar. The patient has normal ankle function, and has returned to active gymnastics. |
| Learning Issues: 1. Aneurysmal bone cyst may reoccur, which often leads to the need for further treatment, such as recurettage. |
| Images of Musculoskeletal Oncology |
| University at Buffalo Department of Orthopaedics |