title: Phosphaturic Mesenchymal Tumor Involving the Head and Neck: A Report of Five Cases with FGFR1 Fluorescence In Situ Hybridization Analysis.
abstract: Phosphaturic mesenchymal tumor (PMT) is a rare neoplasm; however, it is the most common cause of tumor-induced osteomalacia (TIO), a paraneoplastic syndrome characterized by renal phosphate wasting and hypophosphatemia. A subset of PMTs harbours an FGFR1 translocation although this alteration has not been demonstrated in PMT involving a head and neck site. We present a series of five PMTs involving the head and neck and demonstrate the diagnostic utility of fluorescence in situ hybridization (FISH) for detecting FGFR1 translocations. Patients' age and sex, tumor location, original diagnosis, the duration of symptoms, the presence of TIO, biochemical results, and medical management were reviewed. The median age at presentation was 45 (range, 24-58 years) and TIO was present in three cases. Four tumors involved soft tissue and one involved bone. Four out of the five tumors in our series were initially misdiagnosed. Three tumors were ultimately categorized as malignant PMT (two patients developed metastatic disease). FGFR1 translocation was present in two out of four cases and remained unknown in one case. In summary, we report on five cases of PMTs arising in the head and neck and confirm utility of FGFR1 FISH in the diagnosis of a subset of PMT.
authors.affiliation: Department of Pathology and Laboratory Medicine, The Ottawa Hospital - General Campus, Ottawa, ON, Canada.
authors.forename: Jason K
authors.initials: JK
authors.lastname: Wasserman
authors.affiliation: Department of Pathology and Laboratory Medicine, The Ottawa Hospital - General Campus, Ottawa, ON, Canada.
authors.forename: Bibianna
authors.initials: B
authors.lastname: Purgina
authors.affiliation: Department of Pathology and Laboratory Medicine, The Ottawa Hospital - General Campus, Ottawa, ON, Canada.
authors.forename: Chi K
authors.initials: CK
authors.lastname: Lai
authors.affiliation: Department of Pathology and Laboratory Medicine, The Ottawa Hospital - General Campus, Ottawa, ON, Canada.
authors.forename: Denis
authors.initials: D
authors.lastname: Gravel
authors.affiliation: Department of Pathology, Presbyterian University Hospital, University of Pittsburgh Medical Center, PUH A610.3, 200 Lothrop Street, Pittsburgh, PA, 15213, USA.
authors.forename: Alyssa
authors.initials: A
authors.lastname: Mahaffey
authors.affiliation: Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Diana
authors.initials: D
authors.lastname: Bell
authors.affiliation: Department of Pathology, Presbyterian University Hospital, University of Pittsburgh Medical Center, PUH A610.3, 200 Lothrop Street, Pittsburgh, PA, 15213, USA. chioseasi@upmc.edu.
authors.forename: Simion I
authors.initials: SI
authors.lastname: Chiosea
mesh_terms: D000328:Adult; D005260:Female; D006258:Head and Neck Neoplasms / Q000150:complications / Q000235:genetics / Q000473:pathology*; D006801:Humans; D017674:Hypophosphatemia / Q000209:etiology; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008637:Mesenchymoma / Q000150:complications / Q000235:genetics / Q000473:pathology*; D008875:Middle Aged; D009372:Neoplasms, Connective Tissue / Q000209:etiology / Q000473:pathology*; D010018:Osteomalacia; D010257:Paraneoplastic Syndromes / Q000209:etiology; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000235:genetics*; D014178:Translocation, Genetic; D055815:Young Adult
chemical_list: C496348:FGFR1 protein, human; D051496:Receptor, Fibroblast Growth Factor, Type 1
keywords: FGFR1; Fluorescence in situ hybridization; Phosphaturic mesenchymal tumour; Translocation; Tumor-induced osteomalacia