title: Utility of the quantitative Ki-67 proliferation index and CD56 together in the cytologic diagnosis of small cell lung carcinoma and other lung neuroendocrine tumors.
abstract: BACKGROUND
  Distinction of small cell lung carcinoma (SCLC) from non-small cell lung carcinoma (NSCLC) is critical because of the differences in prognosis and management. Patients with SCLC usually present with distant metastasis, and clinicians demand an accurate diagnosis in order to initiate appropriate therapy. Limited cytology material, occasionally with crush artifact, is not uncommon. Therefore, robust cytomorphologic features and a small immunostaining panel would be ideal to differentiate SCLC from NSCLC and other neuroendocrine neoplasms. We evaluated CD56 and the quantitative Ki-67 immunohistochemical panel in comparison to synaptophysin and chromogranin, along with cytomorphology to diagnose SCLC.
  
  
  METHODS
  Eighty-eight cases of SCLC were retrieved from the cytology archives of The Johns Hopkins Hospital. Forty neuroendocrine neoplasms were used as control cases.
  
  
  RESULTS
  SCLCs included 33 lung cases and 55 metastatic lesions. The specimens were obtained by fine needle aspiration, thoracocentesis, bronchoalveolar lavage and abdominal paracentesis. CD56 was expressed in 98.9% of SCLCs, which is significantly more sensitive than synaptophysin and chromogranin. The Ki-67 labeling index was high (>70%) in all cases, which is a reliable marker to differentiate SCLC from other neuroendocrine neoplasms and NSCLC.
  
  
  CONCLUSIONS
  CD56 and quantitative Ki-67 along with cytomorphology is a robust immunohistochemical panel to differentiate SCLC from other neuroendocrine neoplasms and NSCLC.
authors: Department of Pathology, The Johns Hopkins Hospital, Baltimore, Md. 21287, USA.
authors: Gang
authors: G
authors: Zheng
authors: David S
authors: DS
authors: Ettinger
authors: Zahra
authors: Z
authors: Maleki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015142:Baltimore; D044963:Biopsy, Fine-Needle; D018893:Bronchoalveolar Lavage; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D019002:CD56 Antigen / Q000032:analysis*; D049109:Cell Proliferation; D002864:Chromogranins / Q000032:analysis; D003581:Cytodiagnosis / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis*; D008175:Lung Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000737:chemistry / Q000175:diagnosis* / Q000276:immunology / Q000556:secondary; D019152:Paracentesis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D055752:Small Cell Lung Carcinoma / Q000737:chemistry / Q000175:diagnosis* / Q000276:immunology / Q000556:secondary; D016708:Synaptophysin / Q000032:analysis
chemical_list: D019002:CD56 Antigen; D002864:Chromogranins; D019394:Ki-67 Antigen; C522918:NCAM1 protein, human; C569014:SYP protein, human; D016708:Synaptophysin