title: Ewing sarcoma vs lymphoblastic lymphoma. A comparative immunohistochemical study.
abstract: To develop a practical immunohistochemistry panel for distinguishing lymphoblastic lymphoma from Ewing sarcoma (ES), we evaluated 17 ES and 27 lymphoblastic lymphoma and leukemia cases with antibodies to CD99, terminal deoxynucleotidyl transferase (TdT), leukocyte common antigen (LCA), CD43, CD79a, CD20, CD3, vimentin, and neuron-specific enolase (NSE). Three cases were bone lymphomas, 2 initially misdiagnosed as ES. All cases were CD99+. All lymphomas and leukemias were TdT+ compared to none of the ESs. None of the ESs expressed other lymphocytic markers, which were inconsistently expressed in the lymphomas and leukemias: CD43, 33%; LCA, 30%; CD79a, 19%; CD3, 19%; and CD20, 7%. Of the ESs, 88% were vimentin positive compared with 23% of lymphomas and leukemias. Vimentin was stronger and more diffuse in ES. NSE did not reliably stain any cases. When faced with the differential diagnosis of ES vs lymphoblastic lymphoma, an immunohistochemical panel that includes antibodies to CD99 and TdT is useful. Both epitopes are well preserved in fixed and decalcified tissue. A panel composed of antibodies to CD99 and TdT, in conjunction with other lymphocytic markers and vimentin, is highly sensitive and specific.
authors.affiliation: Department of Pathology, Wayne State University School of Medicine, Harper, Hutzel, and Children's Hospitals, and Karmanos Cancer Institute, Detroit, MI, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Lucas
authors.forename: G
authors.initials: G
authors.lastname: Bentley
authors.forename: M E
authors.initials: ME
authors.lastname: Dan
authors.forename: P
authors.initials: P
authors.lastname: Tabaczka
authors.forename: J M
authors.initials: JM
authors.lastname: Poulik
authors.forename: M P
authors.initials: MP
authors.lastname: Mott
mesh_terms: D000071443:12E7 Antigen; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002648:Child; D004253:DNA Nucleotidylexotransferase / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism* / Q000473:pathology*; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000378:metabolism* / Q000473:pathology*; D014746:Vimentin / Q000378:metabolism
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D014746:Vimentin; D004253:DNA Nucleotidylexotransferase