Phosphaturic Mesenchymal Tumor of the Anterior Ethmoid Sinus: A Rare Cause of Tumor-Induced Osteomalacia

Abstract

Phosphaturic mesenchymal tumors (PMTs) are rare, benign neoplasms associated with tumor-induced osteomalacia (TIO). These tumors secrete fibroblast growth factor 23 (FGF23) which causes renal phosphate wasting, hypophosphatemia and skeletal demineralization. We report the case of a 52-year-old male who presented with multiple pathological fractures and hypophosphatemia. Imaging revealed a soft tissue lesion in the right anterior ethmoid sinus. The lesion was excised endoscopically. and histopathology confirmed the diagnosis of PMT. Postoperative normalization of phosphate levels and symptom improvement were observed. This case highlights the significance of prompt diagnosis and surgical management of sinonasal PMTs to prevent long-term complications