99mTc-HYNIC-TOC (99mTc-hydrazinonicotinyl-Tyr3-octreotide) scintigraphy identifying two separate causative tumors in a patient with tumor-induced osteomalacia (TIO)

Clin Nucl Med. 2013 Aug;38(8):664-7. doi: 10.1097/RLU.0b013e3182996293.


Tumors that cause osteomalacia are generally benign fibroblast growth factor-23 producing mesenchymal tumors which can be detected by octreoscan. A 45-year-old man underwent (99m)Tc-HYNIC-TOC scan to detect a possible culprit causing osteomalacia. The images showed abnormal activity in the left humerus and in the right foot. The lesion of the right foot was confirmed pathologically as phosphaturic mesenchymal tumor. After surgical removal of the tumor in the right foot, the patient's symptoms were promptly improved. However, the improvement was transient due to the unresected tumor in the left humerus.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Neoplasms / complications*
  • Bone Neoplasms / diagnostic imaging*
  • Foot / diagnostic imaging
  • Humans
  • Humerus / diagnostic imaging
  • Male
  • Middle Aged
  • Octreotide / analogs & derivatives*
  • Organotechnetium Compounds*
  • Osteomalacia / etiology*
  • Radionuclide Imaging


  • Organotechnetium Compounds
  • technetium Tc 99m hydrazinonicotinyl-Tyr(3)-octreotide
  • Octreotide