Tumor-induced osteomalacia

Abstract

Tumor-induced osteomalacia (TIO) is a paraneoplastic syndrome in which patients present with bone pain, fractures and muscle weakness. The cause is excess production of fibroblast growth factor 23 (FGF-23). In TIO, FGF23 is secreted by mesenchymal tumors, which are small and grow slowly. FGF-23 acts at the renal tubule and impairs phosphate reabsorption, leading to hypophosphatemia and low levels of 1,25-dihidroxivitamin D [1,25(OH)2D].
The treatment of TIO is surgical resection of the causative tumor. For tumors that cannot be located or surgically resected, medical
treatment with oral phosphate supplements and calcitriol is usually successful. However, adherence in some cases is difficult due to
secondary reactions or treatment complications.