Oncogenic osteomalacia induced by a sinonasal tumour: case report and review

Background: Oncogenic osteomalacia (OOM) is a rare paraneoplastic syndrome characterized by hypophosphatemia and overexpression of a phosphaturic agent, fibroblast growth factor 23 (FGF23). OOM is associated with a variety of mesenchymal tumours referred to as phosphaturic mesenchymal tumours. Head and neck regions are concerned in 5-10% of cases. Methods and results: We report the case of a 42-year-old female with OOM caused by a hemangiopericytoma of the left ethmoid sinus. The period between first symptoms and surgical excision of the lesion was approximately 5 years. We also conducted a PubMed-based search to identify all cases of OOM related to sinonasal tumour. Twenty eight cases in the sinonasal area were reported in the literature. Conclusion: OOM is an important diagnosis because resection of the causative tumour results in cure of the disease.