title: Possibility of D2-40 as a diagnostic and tumor differentiation-suggestive marker for some of phosphaturic mesenchymal tumors.
abstract: Phosphaturic mesenchymal tumor (PMT) has been established as a tumor that causes tumor-induced osteomalacia (TIO) associated with mesenchymal neoplasm. Its lineage of differentiation has not been elucidated. Previously, the presence of lymphatic vessels inside PMTs has been documented using an anti-podoplanin antibody; the tumor cells of PMTs were reported to not react with it. In this study of 14 cases of PMTs, we used immunohistochemistry of D2-40, a relatively specific lymphatic endothelial marker, to see if they stained PMTs or not, with particular interest in its reaction with microcystic structures containing lymph-like fluid. We report that most of the PMTs (12 out of 14 cases; 86%) were immunostained by D2-40 in their tumor cells; D2-40-positive lymphatic vessels inside the tumor were also observed. We used a proportion score (0-4+), an intensity score (0-3+), and a total score (the sum of the proportion score and the intensity score) to quantitate our results. We report that 50% of cases (7 out of 14 cases) had a total score ≥ 4+; immunostaining of D2-40 in cases with a total score ≥ 4+ was easy to observe at a glance. Most of the tumor cells lining the microcystic structures were immunostained with D2-40. Thus, D2-40 could be a useful diagnostic marker of PMTs and it might also indicate that PMTs take a lymphatic endothelial immunophenotype.
authors.affiliation: Department of Pathology, Graduate School of Medicine, The University of Tokyo Tokyo, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Tajima
authors.affiliation: Department of Pathology, Graduate School of Medicine, The University of Tokyo Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukayama
mesh_terms: D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009372:Neoplasms, Connective Tissue / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D010018:Osteomalacia; D010257:Paraneoplastic Syndromes
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D014408:Biomarkers, Tumor; C500987:monoclonal antibody D2-40; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23
keywords: D2-40; Phosphaturic mesenchymal tumor; immunohistochemistry