Rickets or osteomalacia develops in some patients with tumours. The tumour produces an unknown factor that causes phosphate wasting from the kidneys, due to an impairment of renal tubular phosphate reabsorption. The syndrome of oncogenic osteomalacia mimics hypophosphataemic rickets or osteomalacia very closely. Tumours are usually benign and slow growing, of the mesenchymal type. This syndrome is reversed when the tumour is successfully removed.
