title: Diagnosis of lymphoproliferative disorders: experience of a single institution in the long-term follow-up of discordant cases.
abstract: OBJECTIVE
  To evaluate the usefulness of morphologic diagnosis, immunophenotyping and immunoglobulin (Ig) and T-cell receptor (TcR) gene rearrangement studies in the diagnosis of lymphoproliferative disorder.
  
  
  METHODS
  A retrospective cohort study with clinical follow-up of controversial cases.
  
  
  METHODS
  Single institution, tertiary care centre.
  
  
  METHODS
  All 273 patients whose lymphoid tissue samples were sent for molecular analysis by Southern blotting over a 4-year period.
  
  
  METHODS
  Patient reports were retrieved from the laboratory data system. Repeat assessment and clinical follow-up was done for discordant cases.
  
  
  METHODS
  Correlation between morphologic features and the results of immunophenotype and gene rearrangement studies of the samples. Value of the different tests in discordant cases.
  
  
  RESULTS
  The 273 samples included 130 of non-Hodgkin's lymphoma (NHL), 23 of Hodgkin's disease, 80 of benign lymphoid hyperplasia, 16 of atypical lymphoid hyperplasia and other diagnoses. Of the 130 NHL cases diagnosed by morphologic study, 22 (17%) did not show gene rearrangement. Of the 80 morphologically benign samples, 4 (5%) showed gene rearrangement, and malignant disease developed later in those patients. Five (31%) of the 16 cases of atypical lymphoid hyperplasia showed gene rearrangement. Six of the remaining 11 cases had no detectable gene rearrangement, but hematologic malignant disease developed. No gene rearrangement was detected in Hodgkin's disease samples. One carcinoma showed gene rearrangement. Of the NHL group, 86% of the B cells and 50% of the T cells showed gene rearrangement. Seven samples showed both Ig and TcR gene rearrangement.
  
  
  CONCLUSIONS
  Gene rearrangement analyses correlate highly with conventional morphologic diagnosis and phenotyping. The detection of gene rearrangement in lymphoid tissue has a high specificity (99%) and a reasonable sensitivity (83%) to the development of a lymphoproliferative disorder.
authors.affiliation: Department of Pathology, Dalhousie University, Halifax, NS. plmis@qe2-hsc.ns.ca
authors.forename: I
authors.initials: I
authors.lastname: Sadek
authors.forename: W
authors.initials: W
authors.lastname: Greer
authors.forename: A
authors.initials: A
authors.lastname: Foyle
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D015321:Gene Rearrangement; D006689:Hodgkin Disease / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D006801:Humans; D016130:Immunophenotyping; D008198:Lymph Nodes / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D008232:Lymphoproliferative Disorders / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013163:Splenomegaly