PET/CT Localization of Phosphaturic Mesenchymal Neoplasm Causing Tumor-Induced Osteomalacia

Abstract

Tumor-induced osteomalacia (TIO), also known as oncogenic osteomalacia (OO), is a rare syndrome characterized by muscle and bone pain, osteomalacia, low serum 1,25-dihydroxy vitamin D, hypophosphatemia, and hyperphosphaturia. This syndrome is caused by a phosphaturic hormone-secreting mesenchymal neoplasm, which is usually benign but often occult. Since excision of the tumor is curative, preoperative tumor localization is essential. However, despite the many radiologic and scintigraphic imaging techniques available, such localization remains a challenge in many cases. We report a case of tumor-induced osteomalacia in which PET-CT successfully localized the occult mesenchymal neoplasm after multiple other imaging tests failed.