title: Fine-needle aspiration biopsy of lymphoproliferative disorders--interpretations based on morphologic criteria alone: results from the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytopathology.
abstract: BACKGROUND
  Diagnosis of lymphoproliferative disorders is one of the most challenging tasks faced by the cytologist. The initial cytomorphologic evaluation of lymphoproliferative lesions directs the choice of ancillary studies that ultimately lead to a diagnosis based on the World Health Organization classification system using a composite of clinical, morphologic, immunophenotypic, and molecular features.
  
  
  OBJECTIVE
  To evaluate the ability of participating laboratories in the College of American Pathologists Interlaboratory Comparison Program in Non-Gynecologic Cytopathology to appropriately categorize lymphoproliferative lesions based solely on cytomorphologic criteria.
  
  
  METHODS
  Laboratory responses for lymph node aspirates were examined. All responses were based on review of glass slides without ancillary immunologic or molecular data available. The benchmarking data provided for each specific diagnosis were analyzed, with a focus on the performance for evaluation of lymphoproliferative lesions.
  
  
  RESULTS
  Based on morphology alone, responses for lymph node aspirates in the Non-Gynecologic Cytopathology program were correct to the exact reference diagnosis for 87.1% of Hodgkin lymphoma. Non-Hodgkin lymphoma was identified in 69.5% of the large cell non-Hodgkin lymphoma cases, of which 66.8% were correctly classified as large cell type. Non-Hodgkin lymphoma was identified in 68.1% of non-Hodgkin lymphoma, other than large cell cases, and of these, 94.7% were identified as other than large cell type.
  
  
  CONCLUSIONS
  The spectrum of specific responses was consistent for lymphoproliferative lesions, with a reasonable differential diagnosis based on cytomorphology alone, which, in practice, facilitates the appropriate choice of immunophenotypic markers and other ancillary studies.
authors.affiliation: Department of Pathology, Fox Chase Cancer Center, 333 Cottman Ave, Philadelphia, PA 19111, USA. na_young@fccc.edu
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Young
authors.forename: Ann T
authors.initials: AT
authors.lastname: Moriarty
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Haja
authors.forename: David C
authors.initials: DC
authors.lastname: Wilbur
mesh_terms: D044963:Biopsy, Fine-Needle; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008232:Lymphoproliferative Disorders / Q000145:classification / Q000473:pathology*; D010340:Pathology, Surgical / Q000592:standards*; D011785:Quality Assurance, Health Care; D012955:Societies, Medical