Phosphaturic mesenchymal tumor without osteomalacia: additional confirmation of the “nonphosphaturic” variant, with emphasis on the roles of FGF23 chromogenic in situ hybridization and FN1-FGFR1 fluorescence in situ hybridization

Sent-Doux K.N.Mackinnon C.JEN-CHIEH LEEFolpe A.L.Habeeb O.2020-03-072020-03-0720180046-8177https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052615762&doi=10.1016%2fj.humpath.2018.02.022&partnerID=40&md5=cd7407ae89b4b6a8dda105fbe823b81chttps://scholars.lib.ntu.edu.tw/handle/123456789/473686Phosphaturic mesenchymal tumor (PMT) is a rare, histologically distinctive neoplasm that classically presents with phosphaturia and tumor-induced osteomalacia (TIO; ie, oncogenic osteomalacia). Both the phosphaturia and the TIO are due to paraneoplastic production of FGF23 (a phosphatonin) by the neoplastic cells, which are genetically characterized by rearrangements of FN1 (most often with FGFR1, and less frequently with FGF1). However, rare cases of PMT present without phosphaturia and TIO (ie, the “nonphosphaturic” variant) and are therefore much more challenging to diagnose. Here, we report the first case of a genetically confirmed, nonphosphaturic PMT, in which the correct diagnosis was established through a combination of careful histologic evaluation, FGF23 chromogenic in situ hybridization, and fluorescence in situ hybridization testing for FN1-FGFR1. ? 2018 Elsevier Inc.FGF23; FN1-FGFR1; Nonphosphaturic; Phosphaturic mesenchymal tumor; Tumor-induced osteomalacia (TIO)[SDGs]SDG3biological marker; CD56 antigen; fibroblast growth factor 23; fibroblast growth factor receptor 1; SATB2 protein; unclassified drug; vimentin; FGFR1 protein, human; fibroblast growth factor; fibroblast growth factor 23; fibroblast growth factor receptor 1; fibronectin; FN1 protein, human; adult; Article; case report; clinical article; fluorescence in situ hybridization; FN1 FGFR1 gene fusion; follow up; gene fusion; human; human tissue; immunohistochemistry; male; middle aged; mitosis rate; neoplasm; oncogenic osteomalacia; osteoclast; phosphaturic mesenchymal tumor; protein expression; rare disease; connective tissue tumor; familial hypophosphatemic rickets; fluorescence in situ hybridization; in situ hybridization; mesenchymoma; metabolism; pathology; procedures; soft tissue tumor; Fibroblast Growth Factors; Fibronectins; Humans; Hypophosphatemia, Familial; In Situ Hybridization; In Situ Hybridization, Fluorescence; Male; Mesenchymoma; Middle Aged; Neoplasms, Connective Tissue; Receptor, Fibroblast Growth Factor, Type 1; Soft Tissue NeoplasmsPhosphaturic mesenchymal tumor without osteomalacia: additional confirmation of the “nonphosphaturic” variant, with emphasis on the roles of FGF23 chromogenic in situ hybridization and FN1-FGFR1 fluorescence in situ hybridizationjournal article10.1016/j.humpath.2018.02.022295141062-s2.0-85052615762