Imaging of malignant infantile osteopetrosis before and after bone marrow transplantation.

BACKGROUND: Malignant infantile osteopetrosis (MIOP) is a sclerosing bone disease caused by absence or defective function of osteoclasts. Since these are of haemopoietic origin, the disease can be cured by allogeneic stem-cell transplantation, but there are no detailed studies of radiological follow-up of these procedures. OBJECTIVE: To investigate the radiological findings at presentation and follow-up in children undergoing bone marrow transplantation (BMT) for MIOP. MATERIALS AND METHODS: Examination of the records and imaging studies of nine paediatric patients undergoing BMT for MIOP during 1988-2000. RESULTS: Presentation findings included characteristic features such as fractures, subperiosteal new bone formation and rachitic appearances. Five children engrafted successfully, allowing assessment of the nature and speed of resolution of radiological features after transplantation. CONCLUSIONS: Radiological improvement was apparent within 2 months of successful engraftment with almost complete resolution of abnormalities after 1 year. Studies in two children who are, respectively, 58 and 83 months post-transplant show complete resolution of all bone changes.