title: Diffuse type of giant-cell tumor of tendon sheath: an ultrastructural study of two cases with cytogenetic support.
abstract: Two cases of the diffuse type of giant-cell tumor of the tendon sheath (GCTTS) are described. Both tumors arose in the vicinity of large joints of the lower extremity, showing similar clinical and radiological features. Histologically, a proliferation of polygonal mononuclear cells was seen, together with osteoclastlike giant cells, foam cells, and siderophages. The tumors were poorly delineated, displaying an infiltrative pattern into the neighboring soft tissues. Immunohistochemically, strong expression of vimentin, neuron-specific enolase, A1-antitrypsin, and CD68 was found in both mono- and multinucleated tumor cells. At the ultrastructural level, mononuclear cells revealed a diverse morphology, displaying features of histiocytelike and fibroblastlike cells, with the former being more numerous. Scarce neurosecretorylike granules, made up of electrondense membrane-bound material, were found in the cytoplasm of the mononuclear cells. Cytogenetic analysis of one case shows the presence of a clonal population with 47 chromosomes and two different translocations, t(2;3) and der(8) t(8;12). Present findings provide further support regarding the neoplasic nature of this tumoral entity.
authors.affiliation: Department of Pathology, Medical School, University of Valencia, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: Ferrer
authors.forename: Asraa
authors.initials: A
authors.lastname: Namiq
authors.forename: Carmen
authors.initials: C
authors.lastname: Carda
authors.forename: Concha
authors.initials: C
authors.lastname: López-Ginés
authors.forename: Ossama
authors.initials: O
authors.lastname: Tawfik
authors.forename: Antonio
authors.initials: A
authors.lastname: Llombart-Bosch
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D020223:Chromosome Painting; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D005870:Giant Cell Tumors / Q000737:chemistry / Q000235:genetics / Q000648:ultrastructure*; D015726:Giant Cells / Q000648:ultrastructure; D006801:Humans; D007124:Immunoenzyme Techniques; D007621:Karyotyping; D008297:Male; D009363:Neoplasm Proteins / Q000032:analysis; D009490:Neurosecretory Systems / Q000648:ultrastructure; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000235:genetics / Q000648:ultrastructure*; D013710:Tendons / Q000737:chemistry / Q000648:ultrastructure*; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins