Eosinophilic granuloma of the capital femoral epiphysis.

Eosinophilic granuloma occurs almost exclusively in the diaphysis or metaphysis, when tubular bones are affected. The investigators present an extremely rare case of eosinophilic granuloma arising at the epiphysis of the femoral head in an 8-year-old boy. Plain radiographs and computed tomography showed a well-circumscribed radiolucent lesion, suggesting chondroblastoma or Brodie's abscess. However, the findings on magnetic resonance images were different from typical features of chondroblastoma or Brodie's abscess. The lesion was curetted. Histological diagnosis was eosinophilic granuloma. Differential diagnoses of a radiolucent lesion at the epiphysis in a child should include, though quite rare, eosinophilic granuloma.