title: Splenic marginal zone lymphoma.
abstract: Splenic marginal zone lymphoma (SMZL) is an indolent small B-cell lymphoma involving the spleen and bone marrow characterized by a micronodular tumoral infiltration that replaces the preexisting lymphoid follicles and shows marginal zone differentiation as a distinctive finding. SMZL cases are characterized by prominent splenomegaly and bone marrow and peripheral blood infiltration. Cells in peripheral blood show a villous cytology. Bone marrow and peripheral blood characteristic features usually allow a diagnosis of SMZL to be performed. Mutational spectrum of SMZL identifies specific findings, such as 7q loss and NOTCH2 and KLF2 mutations, both genes related with marginal zone differentiation. There is a striking clinical variability in SMZL cases, dependent of the tumoral load and performance status. Specific molecular markers such as 7q loss, p53 loss/mutation, NOTCH2 and KLF2 mutations have been found to be associated with the clinical variability. Distinction from Monoclonal B-cell lymphocytosis with marginal zone phenotype is still an open issue that requires identification of precise and specific thresholds with clinical meaning.
authors.affiliation: Servicio de Anatomía Patológica, Hospital Universitario Marqués de Valdecilla, Santander, Spain. Electronic address: mapiris@humv.es.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Piris
authors.affiliation: Servicio de Anatomía Patológica, Hospital Universitario Marqués de Valdecilla, Santander, Spain.
authors.forename: Arantza
authors.initials: A
authors.lastname: Onaindía
authors.affiliation: Servicio de Anatomía Patológica, Hospital Virgen de la Salud, Toledo, Spain.
authors.forename: Manuela
authors.initials: M
authors.lastname: Mollejo
mesh_terms: D002872:Chromosome Deletion; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism; D018442:Lymphoma, B-Cell, Marginal Zone / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009154:Mutation; D051883:Receptor, Notch2 / Q000235:genetics / Q000378:metabolism; D013160:Splenic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: C096161:KLF2 protein, human; D051741:Kruppel-Like Transcription Factors; C497764:NOTCH2 protein, human; D051883:Receptor, Notch2; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53
keywords: Marginal zone; Monoclonal B-cell lymphocytosis; NOTCH2/KLF2; Splenic lymphoma