title: Another look at follicular lymphoma: immunophenotypic and molecular analyses identify distinct follicular lymphoma subgroups.
abstract: OBJECTIVE
  The aim of this study was to analyse the immunophenotypic and molecular features of a large series of follicular lymphomas, focusing in particular on atypical cases that fail to express CD10 and/or bcl-2. Such cases present diagnostic pitfalls, especially with regard to the differential diagnosis from follicular hyperplasia and marginal zone B-cell lymphoma. Therefore, we also included an immunohistochemical evaluation of stathmin, which is strongly expressed by germinal centre B cells, as a putative new marker for follicular lymphomas, particularly those with an atypical phenotype.
  
  
  RESULTS
  Two hundred and five follicular lymphomas were investigated with immunohistochemistry and fluorescence in-situ hybridization (FISH). The use of three distinct anti-bcl-2 antibodies together with CD10 expression data and FISH analysis for bcl-2 and bcl-6 rearrangements allowed subclassification of follicular lymphoma into four distinct subgroups: (i) CD10-positive/bcl-2-positive, (ii) CD10-positive/bcl-2-negative, (iii) CD10-negative/bcl-2-positive, and (iv) CD10-negative/bcl-2-negative. All cases were bcl-6-positive. STMN1 (stathmin) was shown to be helpful in diagnosing bcl-2-negative and/or CD10-negative follicular lymphomas, and in their distinction from marginal zone B-cell lymphoma.
  
  
  CONCLUSIONS
  Combined immunohistological and molecular analyses reveal that follicular lymphomas showing an atypical immunophenotypic and molecular profile exist, and we demonstrate that STMN1 represents a novel useful diagnostic marker for these.
authors.affiliation: Department of Histopathology, University College Hospital, London, UK. t.marafioti@ucl.ac.uk
authors.forename: Teresa
authors.initials: T
authors.lastname: Marafioti
authors.forename: Christiane
authors.initials: C
authors.lastname: Copie-Bergman
authors.forename: Maria
authors.initials: M
authors.lastname: Calaminici
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Paterson
authors.forename: Vishvesh H
authors.initials: VH
authors.lastname: Shende
authors.forename: Hongxiang
authors.initials: H
authors.lastname: Liu
authors.forename: Maryse
authors.initials: M
authors.lastname: Baia
authors.forename: Alan D
authors.initials: AD
authors.lastname: Ramsay
authors.forename: Claudio
authors.initials: C
authors.lastname: Agostinelli
authors.forename: Josette
authors.initials: J
authors.lastname: Brière
authors.forename: Andrew
authors.initials: A
authors.lastname: Clear
authors.forename: Ming-Qing
authors.initials: MQ
authors.lastname: Du
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Piccaluga
authors.forename: Noraidah
authors.initials: N
authors.lastname: Masir
authors.forename: Elizabeth P
authors.initials: EP
authors.lastname: Nacheva
authors.forename: Pierre
authors.initials: P
authors.lastname: Sujobert
authors.forename: Kandavel
authors.initials: K
authors.lastname: Shanmugam
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Grogan
authors.forename: Simon P
authors.initials: SP
authors.lastname: Brooks
authors.forename: Asim
authors.initials: A
authors.lastname: Khwaja
authors.forename: Kirit
authors.initials: K
authors.lastname: Ardeshna
authors.forename: William
authors.initials: W
authors.lastname: Townsend
authors.forename: Stefano A
authors.initials: SA
authors.lastname: Pileri
authors.forename: Corinne
authors.initials: C
authors.lastname: Haioun
authors.forename: David
authors.initials: D
authors.lastname: Linch
authors.forename: John G
authors.initials: JG
authors.lastname: Gribben
authors.forename: Philippe
authors.initials: P
authors.lastname: Gaulard
authors.forename: Peter G
authors.initials: PG
authors.lastname: Isaacson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D003937:Diagnosis, Differential; D005260:Female; D015321:Gene Rearrangement; D019254:Genes, bcl-2; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis / Q000276:immunology; D008224:Lymphoma, Follicular / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051560:Proto-Oncogene Proteins c-bcl-6; D050777:Stathmin / Q000378:metabolism; D055815:Young Adult
chemical_list: C084103:BCL6 protein, human; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051560:Proto-Oncogene Proteins c-bcl-6; C493995:STMN1 protein, human; D050777:Stathmin; D015260:Neprilysin