Tumor-induced osteomalacia (TIO) or oncogenic osteomalacia is a rare paraneoplastic syndrome characterized by debilitating symptom complex of hypophosphatemic osteomalacia associated with tumors, often of mesenchymal origin, which secrete phosphaturic factors. It is an intriguing disorder in clinical endocrine practice. Fibroblast growth factor 23 (FGF23) is the most well-characterized of phosphaturic agents or phosphatonins secreted by these tumors, which have been grouped as ‘phosphaturic mesenchymal tumors’ due to their distinct pathological features. Localization of these tumors is often challenging; however, once localized, complete tumor excision results in dramatic improvement in symptoms and quality of life [1].

This review aims to provide an overview of the epidemiology, pathophysiology, pathology, clinical features, diagnosis, and treatment of TIO, including recent advances and directions for future research in this field. Fig. 1 depicts an overview of brief pathogenesis and typical clinical journey of a patient with TIO.