title: Blastic transformation of hairy cell leukemia.
abstract: OBJECTIVE
  To report blastic transformation of hairy cell leukemia, an uncommon lymphoproliferative disorder of B-cell lineage.
  
  
  METHODS
  Routine histology, cytochemistry, and ultrastructural analysis were used to study this case. Immunoperoxidase studies for leukocyte common antigen (CD45), pan B-cell marker L26 (CD20), and hairy cell leukemia marker DBA.44 were performed. In addition, cell surface marker analysis for CD19, CD20, CD5, CD25, CD11c, and kappa and lambda light chains by flow cytometry was performed.
  
  
  RESULTS
  The patient presented with typical clinical, morphologic, cytochemical, immunophenotypic, and ultrastructural features of hairy cell leukemia. Following splenectomy and prior to institution of any other therapy, he developed a blastic lymphoproliferative malignancy with loss of tartrate-resistant acid phosphatase activity, expression of cell surface markers CD11c and CD25, and immunoreactivity for DBA.44.
  
  
  CONCLUSIONS
  We believe this to be the first report of such a transformation and recommend that the differential diagnosis of blastic transformation of chronic lymphoproliferative disorders include such a possibility.
authors.affiliation: Department of Pathology, Albany Medical College, NY 12208, USA.
authors.forename: T
authors.initials: T
authors.lastname: Nazeer
authors.forename: P
authors.initials: P
authors.lastname: Burkart
authors.forename: H
authors.initials: H
authors.lastname: Dunn
authors.forename: T A
authors.initials: TA
authors.lastname: Jennings
authors.forename: B
authors.initials: B
authors.lastname: Wolf
mesh_terms: D018941:Antigens, CD19 / Q000032:analysis; D018951:Antigens, CD20 / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D001853:Bone Marrow / Q000473:pathology; D018956:CD5 Antigens / Q000032:analysis; D006651:Histocytochemistry; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D007146:Immunoglobulin lambda-Chains / Q000032:analysis; D016167:Integrin alphaXbeta2 / Q000032:analysis; D007943:Leukemia, Hairy Cell / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D017493:Leukocyte Common Antigens / Q000032:analysis; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013154:Spleen / Q000473:pathology
chemical_list: D018941:Antigens, CD19; D018951:Antigens, CD20; D014408:Biomarkers, Tumor; D018956:CD5 Antigens; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D016167:Integrin alphaXbeta2; D015375:Receptors, Interleukin-2; D017493:Leukocyte Common Antigens