Osteochondrodystrophic lesions in chelated thalassemic patients: an histological analysis

Some patients affected by thalassemia major and treated with an iron-chelating drug such as deferioxamine can suffer from severe osteochondrodystrophic lesions of the long bones. These lesions were radiologically and clinically evident in 2.8% of the patients we examined over the last 10 years. The aim of our research was to evaluate the morphology and morphometry of five tibial biopsy specimens taken from thalassemic patients with bone lesions and two bone biopsy specimens taken from thalassemic patients with no alteration of the long bones. All the bone samples showed a similar morphostructure. Abnormal chondrocytes, alteration of cartilage staining pattern, irregular columnar cartilage, and lacunae in the cartilaginous tissue were revealed histologically. Osteoid thickness was either normal or slightly increased. Some bone trabeculae had microfractures and some had cartilagineous oases. In five cases, iron deposition was detectable by Perls' Prussian Blue staining. It can be concluded that even in patients without radiographic signs of lesions, seriously damaged columnar cartilage, altered bone mineralization, and microfractures are common.