Rare Diseases That Impersonate One Another: X-Linked Hypophosphatemia and Tumor-Induced Osteomalacia, a Retrospective Analysis of Discriminating Features.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic disease characterized by frequent fractures, bone pain, muscle weakness, and affected gait. The rarity of TIO and similar presentation to other phosphate-wasting disorders contribute to a high misdiagnosis rate and long time to correct diagnosis. TIO is curable by tumor resection, so accurate diagnosis has significant impact on patients' emotional and economic burden.