{"title":"Oncogenic rickets diagnosed at age 8 and the risk of persistent rickets: a rare case of pediatric-onset tumor-induced osteomalacia.","authors":"Julien Lasnier-Siron, Raul Perret, Acil Jaafar, Thierry Schaeverbeke, Nadia Mehsen Cetre","doi":"10.1007/s00198-025-07469-2","DOIUrl":null,"url":null,"abstract":"<p><p>Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by excess fibroblast growth factor 23 (FGF23), leading to hypophosphatemia and osteomalacia. It typically manifests in adulthood, with pediatric cases being exceedingly rare. Early diagnosis is critical to prevent irreversible skeletal deformities. We report the case of a 19-year-old man with severe lower limb deformities and loss of ambulation since childhood. Initially misdiagnosed with X-linked hypophosphatemia (XLH) and treated with burosumab, genetic testing ruled out hereditary hypophosphatemic disorders. Further evaluation revealed an FGF23-secreting mesenchymal tumor in the right femur, confirming TIO. Surgical resection of the tumor led to biochemical remission, while burosumab treatment contributed to pain relief, functional improvement, and increased bone mineral density. Histological examination suggested potential tumor modifications linked to burosumab exposure. This case highlights the diagnostic challenge of pediatric-onset TIO, emphasizing the importance of considering oncogenic rickets in cases of early hypophosphatemic osteomalacia with severe deformities. The risk of persistent skeletal abnormalities despite treatment underscores the need for early recognition and intervention. Moreover, burosumab showed clinical efficacy in managing hypophosphatemia and symptoms, suggesting a therapeutic role in TIO when surgery is delayed or inoperable. Pediatric-onset TIO is an underrecognized entity that can lead to severe disability if not diagnosed early. This case underscores the importance of early tumor identification.</p>","PeriodicalId":19638,"journal":{"name":"Osteoporosis International","volume":" ","pages":"1481-1485"},"PeriodicalIF":5.4000,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12373540/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Osteoporosis International","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s00198-025-07469-2","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/5/13 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"ENDOCRINOLOGY & METABOLISM","Score":null,"Total":0}
引用次数: 0
Abstract
Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by excess fibroblast growth factor 23 (FGF23), leading to hypophosphatemia and osteomalacia. It typically manifests in adulthood, with pediatric cases being exceedingly rare. Early diagnosis is critical to prevent irreversible skeletal deformities. We report the case of a 19-year-old man with severe lower limb deformities and loss of ambulation since childhood. Initially misdiagnosed with X-linked hypophosphatemia (XLH) and treated with burosumab, genetic testing ruled out hereditary hypophosphatemic disorders. Further evaluation revealed an FGF23-secreting mesenchymal tumor in the right femur, confirming TIO. Surgical resection of the tumor led to biochemical remission, while burosumab treatment contributed to pain relief, functional improvement, and increased bone mineral density. Histological examination suggested potential tumor modifications linked to burosumab exposure. This case highlights the diagnostic challenge of pediatric-onset TIO, emphasizing the importance of considering oncogenic rickets in cases of early hypophosphatemic osteomalacia with severe deformities. The risk of persistent skeletal abnormalities despite treatment underscores the need for early recognition and intervention. Moreover, burosumab showed clinical efficacy in managing hypophosphatemia and symptoms, suggesting a therapeutic role in TIO when surgery is delayed or inoperable. Pediatric-onset TIO is an underrecognized entity that can lead to severe disability if not diagnosed early. This case underscores the importance of early tumor identification.
期刊介绍:
An international multi-disciplinary journal which is a joint initiative between the International Osteoporosis Foundation and the National Osteoporosis Foundation of the USA, Osteoporosis International provides a forum for the communication and exchange of current ideas concerning the diagnosis, prevention, treatment and management of osteoporosis and other metabolic bone diseases.
It publishes: original papers - reporting progress and results in all areas of osteoporosis and its related fields; review articles - reflecting the present state of knowledge in special areas of summarizing limited themes in which discussion has led to clearly defined conclusions; educational articles - giving information on the progress of a topic of particular interest; case reports - of uncommon or interesting presentations of the condition.
While focusing on clinical research, the Journal will also accept submissions on more basic aspects of research, where they are considered by the editors to be relevant to the human disease spectrum.