Tumor-induced osteomalacia (TIO) is a rare paraneoplasic syndrome with overproduction of fibroblast growth factor 23 as a phosphaturic agent, leading to chronic hyperphosphaturia and hypophosphatemia, associated with inappropriately normal or low levels of 1,25-dihydroxyvitamin D. Diagnosis of this disease is often challenging. The following case report described a middle-aged man with symptoms of bone pain and severe muscle weakness, who was found to have TIO. The tumor responsible for the symptoms was localized on his thigh and its resection resulted […]