UNLABELLED: Hypophosphataemic rickets was diagnosed in a 6-year-old boy with a negative family history. After 16 years of medical treatment he developed a malignant sarcoma of the right distal thigh. Removal of the tumour by high amputation of the leg resulted in disappearance of the phosphate leak. In spite of surgery and chemotherapy, the patient died due to extensive lung metastases. Retrospective analysis of the initial X-ray films showed a benign lesion on the lateral side of the right distal femur. This lesion is believed to be at the origin of the rickets. This is the first paediatric case reported with malignant degeneration of a benign tumour causing rickets. CONCLUSION: Patients with the classical hallmarks of X-linked, familial hypophosphataemic rickets but no affected family members should have a careful periodic search for a tumour, even years after onset of the disorder.
UNLABELLED: Hypophosphataemic rickets was diagnosed in a 6-year-old boy with a negative family history. After 16 years of medical treatment he developed a malignant sarcoma of the right distal thigh. Removal of the tumour by high amputation of the leg resulted in disappearance of the phosphate leak. In spite of surgery and chemotherapy, the patient died due to extensive lung metastases. Retrospective analysis of the initial X-ray films showed a benign lesion on the lateral side of the right distal femur. This lesion is believed to be at the origin of the rickets. This is the first paediatric case reported with malignant degeneration of a benign tumour causing rickets. CONCLUSION:Patients with the classical hallmarks of X-linked, familial hypophosphataemic rickets but no affected family members should have a careful periodic search for a tumour, even years after onset of the disorder.