Persistent urinary phosphate wasting in a patient with metastatic breast cancer: What's your diagnosis? Article

Full Text via DOI: 10.5414/CN110139 Web of Science: 000607203500005
International Collaboration

Cited authors

  • Bhasin B, Velez JCQ


  • Tumor-induced osteomalacia (TIO) can cause severe, persistent hypophosphatemia due to high fibroblast growth factor-23 (FGF-23) levels, which lead to urinary phosphate wasting. TIO is frequently encountered in association with mesenchymal tumors and responds well to resection of the primary malignancy. Rarely, TIO may be seen as a paraneoplastic phenomenon with solid organ malignancies where correction of biochemical abnormalities requires ongoing phosphorus replacement. We report a case of TIO in a patient with metastatic breast cancer complicated by increased parathyroid hormone release secondary to denosumab-induced hypocalcemia. The patient required intensive intravenous and oral phosphate supplementation in addition to vitamin D repletion. A high index of clinical suspicion can yield the correct diagnosis where TIO arises in the setting of a solid organ tumor and help the clinician appropriately manage these challenging cases.

Publication date

  • 2021

Published in

International Standard Serial Number (ISSN)

  • 0301-0430

Number of pages

  • 5

Start page

  • 99

End page

  • 103


  • 95


  • 2