Oncogenic osteomalacia: A case report and review of the literarture

Abstract

Oncogenic osteomalacia is a rare paraneoplastic syndrome characterized by severe hypophosphoremia due to renal phosphate wasting and osteomalacia clinically near to hereditary hypophosphoremic rickets. This disorder is induced by a benign tumor which belongs to the group of « phosphaturic mesenchymal tumor mixed connective tissue variant » secreting phosphaturic factors. We report the case of a 54-year old man who presented with diffuse bone pain and bilateral hip pain evolving for 3 years. Physical examination revealed a subcutaneous tumor of the left
flank. A radiographic skeletal survey showed signs of osteomalacia with an overall « washed-out » appearance of the bone, cuneiform aspect of dorsolombar vertebral bodies and bilateral fracture of femoral necks. Serum Fibroblast Growth Factor 23 concentration was high. The patient had total bilateral hips arthroplasty and surgical removal of the tumor of the flank was performed. There was rapid improvement and the laboratory values returned to normal.

Keywords: Oncogenic, Osteomalacia, Mesenchymal, Tumor, fibroblast growth factor.