title: Surface Light Chain Expression in Primary Mediastinal Large B-Cell Lymphomas by Multiparameter Flow Cytometry.
abstract: OBJECTIVE
  Primary mediastinal large B-cell lymphoma (PMLBL) is an aggressive B-cell lymphoma typically localized to the mediastinum. To date, no study has undertaken a comprehensive analysis of this entity by multiparameter flow cytometry.
  
  
  METHODS
  Cases of PMLBL with diagnostic flow cytometry were identified from pathology databases of Boston Children's Hospital, Brigham and Women's Hospital, and Stanford Hospital.
  
  
  RESULTS
  Most of these patients with PMLBL were women with a median age of 30 years who had stage 1 disease that lacked bone marrow involvement. By flow cytometry, 50% of all PMLBLs showed restricted surface immunoglobulin expression. When comparing patients with PMLBL by the absence or presence of surface light chain immunoglobulins, no differences were seen in the morphologic appearance; expression of CD23, CD30, or CD10; age at presentation; or clinical stage (P > .5 for all). In addition, both groups showed similarly good survival outcomes and were alive at last follow-up (11/14 [79%]; P = .542).
  
  
  CONCLUSIONS
  This multi-institutional study demonstrates that 50% of PMLBLs can present with clonal surface light chain expression and that PMLBL is more immunophenotypically diverse than previously described. Furthermore, our findings suggest that the absence or presence of surface light chains should not be used as criteria for diagnosis in this disease.
authors.affiliation: From the Boston Children's Hospital, Boston, MA; Olga.Weinberg@childrens.harvard.edu.
authors.forename: Olga K
authors.initials: OK
authors.lastname: Weinberg
authors.affiliation: Brigham and Women's Hospital, Boston, MA; and.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Rodig
authors.affiliation: Brigham and Women's Hospital, Boston, MA; and.
authors.forename: Olga
authors.initials: O
authors.lastname: Pozdnyakova
authors.affiliation: Stanford University, Stanford, CA.
authors.forename: Li
authors.initials: L
authors.lastname: Ren
authors.affiliation: Stanford University, Stanford, CA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Arber
authors.affiliation: Stanford University, Stanford, CA.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Ohgami
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000032:analysis* / Q000276:immunology; D016130:Immunophenotyping; D016393:Lymphoma, B-Cell / Q000276:immunology / Q000473:pathology*; D008297:Male; D008479:Mediastinal Neoplasms / Q000276:immunology / Q000473:pathology*; D008875:Middle Aged; D055815:Young Adult
chemical_list: D007147:Immunoglobulin Light Chains
keywords: Flow cytometry; Primary mediastinal large B-cell lymphoma; Surface immunoglobulin