title: ERG and FLI1 are useful immunohistochemical markers in phosphaturic mesenchymal tumors.
abstract: Phosphaturic mesenchymal tumors (PMT) are the most common cause of tumor-induced osteomalacia (TIO) related to mesenchymal neoplasms. The lineage of differentiation of PMTs has not been elucidated in existing literature. Fourteen cases of PMT were analyzed for this study to elucidate its lineage. We used vascular and/or lymphatic endothelial markers for the immunohistochemical analysis, which included CD31, CD34, factor VIII-related antigen, podoplanin, Freund's leukemia integration site 1 (FLI1), and avian v-ets erythroblastosis virus E26 oncogene homolog (ERG). FLI1 and ERG were stained in all cases with proportion of immunopositive tumor cells largely more than 50 %; staining intensity was moderate or strong for both FLI1 and ERG. The tumor cells were stained with CD31 and/or CD34, with significantly less staining than observed for FLI1 and ERG. The tumor cells were completely immunonegative for factor VIII-related antigen and podoplanin. FLI1 and ERG are known to have considerable specificity to endothelial cells; ERG is more widely equipped in surgical pathology laboratories than FLI1. We concluded that ERG (or FLI1 if available) is useful marker for the diagnosis of PMT, and that PMTs may have an endothelial cell lineage.
authors.affiliation: Department of Pathology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. stajima-tky@umin.ac.jp.
authors.forename: Shogo
authors.initials: S
authors.lastname: Tajima
authors.affiliation: Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan.|Fujii Memorial Institute of Medical Sciences, Tokushima University, Tokushima, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Takashi
authors.affiliation: Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Ito
authors.affiliation: Fujii Memorial Institute of Medical Sciences, Tokushima University, Tokushima, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Fukumoto
authors.affiliation: Department of Pathology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukuyama
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D005260:Female; D006801:Humans; D007015:Hypophosphatemia, Familial / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry; D008297:Male; D008648:Mesoderm / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology*; D051789:Proto-Oncogene Protein c-fli-1 / Q000378:metabolism*; D000071230:Transcriptional Regulator ERG / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C072312:ERG protein, human; C078433:FLI1 protein, human; D051789:Proto-Oncogene Protein c-fli-1; D000071230:Transcriptional Regulator ERG
keywords: CD31; CD34; ERG; FLI1; Phosphaturic mesenchymal tumor