title: Aberrant NK cell associated marker (CD56 and CD57) expression in chronic lymphocytic leukemia.
abstract: BACKGROUND
  Chronic lymphocytic leukemia (CLL) is one of the commonest leukemias that has been reported extensively throughout the literature. The characteristic phenotype includes co-expression of CD5 and CD23, along with dim expression of light chain and CD22/CD79b, with lack of FMC7. The immunophenotypic scoring system given by Matutes has been used to differentiate CLL from non-CLL chronic lymphoproliferative disorders. Various aberrancies have been described in CLL cases, including abnormal (dim or bright) expression of B cell markers and lineage infidel T cell, myelomonocytic, or rarely Natural killer (NK) cells markers. However, the aberrant co-expression of CD56 and CD57 has not yet been reported.
  
  
  RESULTS
  We hereby report a case of 62-year female with a typical CLL phenotype and Matutes score of 5, showing the expression of CD56 and CD57.
  
  
  CONCLUSIONS
  This entity may represent a rare subtype of CLL which needs to be studied more extensively for its prognostic implications. This is the first report of CLL with aberrant CD56 and CD57 expression.
authors.affiliation: Department of Pathology and Laboratory Medicine, Medanta the Medicity, Gurgaon, Haryana, 122 001, India.
authors.forename: Pranav
authors.initials: P
authors.lastname: Dorwal
authors.affiliation: Department of Pathology and Laboratory Medicine, Medanta the Medicity, Gurgaon, Haryana, 122 001, India.
authors.forename: Simmi
authors.initials: S
authors.lastname: Mehra
authors.affiliation: Department of Pathology and Laboratory Medicine, Medanta the Medicity, Gurgaon, Haryana, 122 001, India.
authors.forename: Amit
authors.initials: A
authors.lastname: Pande
authors.affiliation: Department of Pathology and Laboratory Medicine, Medanta the Medicity, Gurgaon, Haryana, 122 001, India.
authors.forename: Dharmendra
authors.initials: D
authors.lastname: Jain
authors.affiliation: Department of Pathology and Laboratory Medicine, Medanta the Medicity, Gurgaon, Haryana, 122 001, India.
authors.forename: G
authors.initials: G
authors.lastname: Smeeta
authors.affiliation: Department of Pathology and Laboratory Medicine, Medanta the Medicity, Gurgaon, Haryana, 122 001, India.
authors.forename: Ritesh
authors.initials: R
authors.lastname: Sachdev
authors.affiliation: Department of Pathology and Laboratory Medicine, Medanta the Medicity, Gurgaon, Haryana, 122 001, India.
authors.forename: Vimarsh
authors.initials: V
authors.lastname: Raina
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D019002:CD56 Antigen / Q000032:analysis*; D018959:CD57 Antigens / Q000032:analysis*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D007694:Killer Cells, Natural / Q000276:immunology* / Q000473:pathology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged; D010641:Phenotype
chemical_list: D014408:Biomarkers, Tumor; D019002:CD56 Antigen; D018959:CD57 Antigens; C522918:NCAM1 protein, human
keywords: CD56; CD57; CLL; flow cytometry