Tumor-induced osteomalacia: An overview

Best Pract Res Clin Endocrinol Metab. 2024 Mar;38(2):101834. doi: 10.1016/j.beem.2023.101834. Epub 2023 Oct 20.

Abstract

Tumor-induced osteomalacia (TIO) is rare paraneoplastic syndrome of hypophosphatemic osteomalacia, caused by phosphaturic factors secreted by small mesenchymal origin tumors with distinct pathological features, called 'phosphaturic mesenchymal tumors'. FGF23 is the most well-characterized of the phosphaturic factors. Tumors are often small and located anywhere in the body from head to toe, which makes the localisation challenging. Functional imaging by somatostatin receptor-based PET imaging is the first line investigation, which should be followed with CT or MRI based anatomical imaging. Once localised, complete surgical excision is the treatment of choice, which brings dramatic resolution of symptoms. Medical management in the form of phosphate and active vitamin D supplements is given as a bridge to surgical management or in inoperable/non-localised patients. This review provides an overview of the epidemiology, pathophysiology, pathology, clinical features, diagnosis, and treatment of TIO, including the recent advances and directions for future research in this field.

Keywords: fibroblast growth factor 23 (FGF23); oncogenic osteomalacia; phosphaturic mesenchymal tumour- mixed connective tissue (PMT MCT); tumour induced osteomalacia.

Publication types

  • Review

MeSH terms

  • Humans
  • Mesenchymoma* / complications
  • Mesenchymoma* / diagnosis
  • Mesenchymoma* / pathology
  • Neoplasms, Connective Tissue* / diagnosis
  • Neoplasms, Connective Tissue* / etiology
  • Neoplasms, Connective Tissue* / therapy
  • Osteomalacia* / diagnosis
  • Osteomalacia* / etiology
  • Osteomalacia* / pathology
  • Paraneoplastic Syndromes* / diagnosis
  • Paraneoplastic Syndromes* / etiology
  • Paraneoplastic Syndromes* / pathology

Supplementary concepts

  • Oncogenic osteomalacia