title: Development of tumor-induced osteomalacia in a subcutaneous tumor, defined by venous blood sampling of fibroblast growth factor-23.
abstract: A 25-year-old man with severe lumbago was referred to our department for further evaluation. Serum phosphate and TmP/GFR levels were decreased. Physical examination revealed an elastic tumor in the instep of the right foot, which the patient reported having since the age of 10 years. He had no symptoms of osteomalacia at that time. Within the recent years, the tumor had grown in size and the patient developed lumbago. To examine the existence of a fibroblast growth factor-23 (FGF-23)-producing tumor, venous blood was collected from four main veins. FGF-23 levels were significantly increased in the right femoral vein, compared with other veins. After the resection of the tumor, the histopathology was consistent with a phosphaturic mesenchymal tumor (mixed connective tissue variant). Taken together, these results indicated that the development of osteomalacia in this patient was associated with the production of FGF-23 in the subcutaneous tumor.
authors: The First Department of Internal Medicine, Aomori City Hospital, Japan.
authors: Eriko
authors: E
authors: Ogura
authors: Kazunori
authors: K
authors: Kageyama
authors: Seiji
authors: S
authors: Fukumoto
authors: Norito
authors: N
authors: Yagihashi
authors: Yoshiko
authors: Y
authors: Fukuda
authors: Toru
authors: T
authors: Kikuchi
authors: Mitsuo
authors: M
authors: Masuda
authors: Toshihiro
authors: T
authors: Suda
mesh_terms: D000328:Adult; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D006801:Humans; D008297:Male; D010018:Osteomalacia / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D012983:Soft Tissue Neoplasms / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D040521:Subcutaneous Tissue / Q000378:metabolism* / Q000473:pathology
chemical_list: C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23