Tumor-induced osteomalacia: a clinical case report

Abstract

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome usually caused by small-sized tumors. Tumors secrete fibroblast growth factor 23 (FGF23), which has a phosphaturic effect. The clinical signs of TIO are non-specific, and include fatigue, bone pain and muscle weakness, which makes timely diagnosis of the disease difficult and treatment is often delayed. Well-timed diagnosis is essential and combined with complete tumor resection it leads to complete relief of symptoms and good postoperative prognosis. In cases of undetected tumors, medical treatment with phosphate supplements and active vitamin D medications is usually successful, however, treatment is associated with numerous complications and side effects can be burdensome for the patients. Due to the risk of recurrence or metastasis, patients with TIO require long-term management and follow-up. In this article, we present a clinical case of successful diagnosis and treatment of TIO in a young patient with type 1 diabetes mellitus.

Keywords

• hypophosphatemia
• tumor-induced osteomalacia
• fibroblast growth factor-23
• mesenchymal tumor