Faculty Collaboration Database

Persistent phosphaturic mesenchymal tumor causing tumor-induced osteomalacia treated with image-guided ablation. Osteoporos Int 2021 Sep;32(9):1895-1898

Date

03/04/2021

Pubmed ID

33655402

DOI

10.1007/s00198-020-05795-1

Scopus ID

2-s2.0-85102065426 (requires institutional sign-in at Scopus site)   4 Citations

Abstract

Phosphaturic mesenchymal tumors (PMTs) can present with vague symptoms of diffuse bone pain with pathologic fractures that often lead to a delayed diagnosis. We present a 60-year-old patient with a PMT that was persistently hypophosphatemic after resection, who was then successfully treated with cryoablation of the tumor. Tumor-induced osteomalacia (TIO) is a rare cause of hypophosphatemia characterized by vague symptoms of gradual muscle weakness and diffuse bone pain with pathologic fractures that often lead to a delayed diagnosis. This condition is usually caused by benign phosphaturic mesenchymal tumors (PMTs). Here, we present a case of persistent PMT after surgical resection treated with image-guided ablation. We present the patient's clinical examinations and laboratory findings (phosphorus, 1,25 (OH)₂D, FGF-23, Intact PTH). Representative histologic images of a PMT are also presented. A 61-year-old male was evaluated for persistent hypophosphatemia and presumed osteomalacia. Six years earlier, he underwent surgical excision of a left ischial mass after presenting with TIO. The pathology was consistent with a PMT; however, hypophosphatemia persisted suggesting incomplete resection. He was treated with calcitriol and phosphate salts. A PET Ga68 dotatate scan of the patient revealed an avid left ischial mixed lytic and sclerotic lesions with marked amount of radiotracer uptake, suggesting persistent tumor. The patient was resistant to re-excision of the tumor due to the extended recovery period from his prior surgery and was treated instead with cryoablation of the tumor. His biochemical findings of hypophosphatemia and elevated FGF23 resolved after the ablation and have remained normal for 5 months after surgery. In patients with TIO, wide surgical excision is the treatment of choice. When this is not possible, image-guided ablation is an alternative therapeutic option.

Author List

Horng JC, Van Eperen E, Tutton S, Singh R, Shaker JL, Wooldridge AN

Authors

Joseph L. Shaker MD Professor in the Medicine department at Medical College of Wisconsin
Adam Neal Wooldridge MD, MPH Assistant Professor in the Orthopaedic Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Humans
Hypophosphatemia
Male
Middle Aged
Neoplasms, Connective Tissue
Osteomalacia
Paraneoplastic Syndromes
Soft Tissue Neoplasms