Background: Tumor-induced osteomalacia (TIO) is an extremely rare paraneoplastic syndrome associated with mesenchymal tumors in the craniofacial region.
Methods: We treated a 24-year-old Japanese woman with paranasal sinus tumor and a low serum phosphate level who presented with nasal obstruction and systemic bone fractures. Serum fibroblast growth factor 23 (FGF-23) was measured before and after surgery.
Results: After surgery, her symptoms were resolved and the serum phosphate and FGF-23 levels became normalized.
Conclusion: FGF-23 is thought to be a useful diagnostic marker in patients with craniofacial tumors associated with multiple systemic fractures.