title: Transgelin is a novel marker of smooth muscle differentiation that improves diagnostic accuracy of leiomyosarcomas: a comparative immunohistochemical reappraisal of myogenic markers in 900 soft tissue tumors.
abstract: Immunohistochemical use of myogenic markers serves to define smooth or skeletal muscle differentiation in soft tissue tumors. Establishing smooth muscle differentiation in malignant lesions can be challenging in some cases. We immunohistochemically examined 900 soft tissue tumors selected from the French Sarcoma Group's archived tissue collection, which contains a large number of leiomyosarcomas. The four most widely used smooth muscle diagnostic markers were evaluated (smooth muscle actin, desmin, h-caldesmon and calponin), and compared with a novel marker, transgelin. The diagnostic performance of each marker was statistically assessed in terms of sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (A), in leiomyosarcomas versus all other sarcomas including gastrointestinal stromal tumors (GIST), and second in leiomyosarcomas versus specific tumor types. In leiomyosarcomas versus all other sarcomas including GIST, transgelin emerged as the best diagnostic marker (Se: 83%, Sp: 82%, PPV: 67%, NPV: 92%, A: 83%), compared with smooth muscle actin (Se: 75%, Sp: 83, PPV: 66%, NPV: 89%, A: 81%), desmin (Se: 45%, Sp: 88%, PPV: 62%, NPV: 79%, A: 75%), h-caldesmon (Se: 50%, Sp: 90%, PPV: 67%, NPV: 81%, A: 78%) and calponin (Se: 76%, Sp: 70, PPV: 52%, NPV: 87%, A: 71%). In leiomyosarcomas compared with other specific tumor types such as undifferentiated pleomorphic sarcoma and myxofibrosarcoma, the accuracy for transgelin varied from 80 to 87% whereas it was lower for all other markers (between 51 and 80%). These results indicate that transgelin could be used in practice as an additional marker useful for decision making, especially in those tumors with incomplete immunophenotypes.
authors.affiliation: Department of Biology, Unit of Morphological and Molecular Pathology, Centre Oscar Lambret, Lille Cedex, France.
authors.forename: Yves-Marie
authors.initials: YM
authors.lastname: Robin
authors.forename: Nicolas
authors.initials: N
authors.lastname: Penel
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Pérot
authors.forename: Agnes
authors.initials: A
authors.lastname: Neuville
authors.forename: Valérie
authors.initials: V
authors.lastname: Vélasco
authors.forename: Dominique
authors.initials: D
authors.lastname: Ranchère-Vince
authors.forename: Philippe
authors.initials: P
authors.lastname: Terrier
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Coindre
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D002454:Cell Differentiation; D006801:Humans; D007150:Immunohistochemistry; D007890:Leiomyosarcoma / Q000175:diagnosis* / Q000378:metabolism; D008840:Microfilament Proteins / Q000032:analysis / Q000096:biosynthesis*; D009124:Muscle Proteins / Q000032:analysis / Q000096:biosynthesis*; D009130:Muscle, Smooth / Q000473:pathology; D011237:Predictive Value of Tests; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D008840:Microfilament Proteins; D009124:Muscle Proteins; C051615:transgelin