title: Splenic marginal zone B-cell lymphoma: a distinct clinicopathological and molecular entity. Recent advances in ontogeny and classification.
abstract: OBJECTIVE
  Indolent B-cell lymphomas that are supposed to derive from marginal zone encompass three distinct entities: extranodal marginal zone lymphoma (MZL) or mucosa-associated lymphatic tissue (MALT), nodal MZL (NMZL) and splenic MZL (SMZL). Although MALT lymphoma is well characterized and extensively studied at the clinical and molecular levels, SMZL and NMZL remain incompletely characterized. However, during the last years, the clinical and molecular heterogeneity of SMZL has been clarified. The recent 2008 WHO classification has maintained the distinction between the three diseases according to the organ where it arises and introduced a new provisional category of unclassified splenic lymphoma for overlapping entities, splenic diffuse red pulp lymphoma (SDRPL) and hairy cell leukemia-variant (HCL-V).
  
  
  RESULTS
  Recent findings in SMZL contributed to a better characterization, including the few cases associated with hepatitis C, the recurrence of 7q deletion and the possibility of CD5 expression. Furthermore, the peculiar pattern of immunoglobulin heavy chain genes mutations and the biased usage of immunoglobulin heavy chain variable region genes (IGHV)1-2 segment are suggestive of a T-independent antigen driven proliferation, at least at initial steps. This review will focus on recent findings and differential diagnosis with SDRPL and HCL-V.
  
  
  CONCLUSIONS
  The conjunction of morphologic, cytogenetic and clinical data has increased diagnosis reproducibility.
authors.affiliation: Hospices Civils de Lyon, Service d'Anatomie Pathologique, Centre Hospitalier Lyon Sud, Pierre Bénite, Université Lyon 1, UMR CNRS 5239 Equipe Pathologie des Cellules Lymphoides, Lyon, France. alexandra.traverse-glehen@chu-lyon.fr
authors.forename: A
authors.initials: A
authors.lastname: Traverse-Glehen
authors.forename: L
authors.initials: L
authors.lastname: Baseggio
authors.forename: G
authors.initials: G
authors.lastname: Salles
authors.forename: P
authors.initials: P
authors.lastname: Felman
authors.forename: F
authors.initials: F
authors.lastname: Berger
mesh_terms: D003131:Combined Modality Therapy; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000145:classification* / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D010641:Phenotype; D013156:Splenectomy; D013160:Splenic Neoplasms / Q000145:classification* / Q000378:metabolism / Q000473:pathology / Q000628:therapy