title: Cytochemical staining and flow cytometry methods applied to the diagnosis of acute leukemia in the pediatric population: an assessment of relative usefulness.
abstract: BACKGROUND
  Cytochemical staining has been used in the diagnosis of acute leukemia for more than 20 years. The general availability of flow cytometers and an extensive panel of antibody reagents useful for characterizing blood cell lineage question the usefulness of continuing routine use of the cytochemical staining for the diagnosis of acute leukemia.
  
  
  METHODS
  Test results were evaluated in 122 (n = 122; 112 with acute lymphocytic leukemia and 10 with acute myeloid leukemia) patients selected from among 320 patients with acute leukemia at Texas Children's Hospital in 1997 and 1998. Results were selected for review if the clinical encounter represented the initial diagnostic work-up and if data were available from cytochemical staining and flow cytometry studies.
  
  
  RESULTS
  Cell lineage classification derived from flow cytometry and cytochemical stains were in agreement in all cases. Definitive diagnoses were feasible using flow cytometry results alone in 120 of 122 patients (98.4%) as compared with only 99 of 122 patients (81.2%) when only cytochemical staining results were considered. In two patients with inconclusive flow cytometry results, cytochemical staining alone provided information sufficient for diagnosis.
  
  
  CONCLUSIONS
  Results from this study indicate that with few exceptions, flow cytometry studies alone provide sufficient information for diagnosis and management of acute leukemia in children. Nevertheless, cytochemical staining should be available for those cases in which flow cytometry results fail to allow a definitive diagnosis. A modified testing protocol is recommended.
authors.affiliation: Department of Pathology, Baylor College of Medicine and Texas Children's Hospital, Houston, USA.
authors.forename: P
authors.initials: P
authors.lastname: Mhawech
authors.forename: G J
authors.initials: GJ
authors.lastname: Buffone
authors.forename: S P
authors.initials: SP
authors.lastname: Khan
authors.forename: M V
authors.initials: MV
authors.lastname: Gresik
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000465:Algorithms; D001391:Azo Compounds; D001856:Bone Marrow Examination / Q000379:methods; D043182:Carboxylesterase; D002265:Carboxylic Ester Hydrolases / Q000032:analysis; D019070:Cell Lineage; D002648:Child; D002675:Child, Preschool; D004396:Coloring Agents; D005240:Feasibility Studies; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007938:Leukemia / Q000145:classification / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D008297:Male; D009281:Naphthalenes; D009363:Neoplasm Proteins / Q000032:analysis; D010503:Periodic Acid-Schiff Reaction; D009195:Peroxidase / Q000032:analysis; D012189:Retrospective Studies; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D009281:Naphthalenes; D009363:Neoplasm Proteins; C016118:Sudan Black B; D009195:Peroxidase; D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase