title: Diagnostic value of fine needle aspirates processed by ThinPrep® for the assessment of axillary lymph node status in patients with invasive carcinoma of the breast.
abstract: OBJECTIVE
  To evaluate the utility of ThinPrep® as an optional specimen processing method for the detection of axillary lymph node metastasis of invasive breast carcinoma.
  
  
  METHODS
  A computer SNOMED search from the file at our institution between January 2003 and August 2011 retrieved a total of 209 fine needle aspiration (FNA) specimens of axillary lymph nodes prepared by ThinPrep and followed by axillary lymph node biopsy and/or dissection. Original cytological diagnoses and corresponding histological diagnoses were documented. Using the histological diagnoses as the gold standard, the diagnostic parameters including sensitivity, specificity, positive (PPV) and negative predictive values (NPV) and diagnostic accuracy were calculated. Both cytology and histology slides from cyto-histologically discrepant cases were reviewed.
  
  
  RESULTS
  Out of a total of 209 specimens, 193 (92%) had adequate diagnostic material while the remaining 16 specimens (8%) were inadequate for cytological assessment. The diagnostic specimens included 168 invasive ductal carcinomas (IDC), 15 invasive lobular carcinomas (ILC) and 10 mixed carcinomas (IDC and ILC). Excluding 19 cases with malignant cells on FNA in which no residual tumour was found in fibrotic lymph nodes after neoadjuvant therapy (cytology and histology confirmed on review) ThinPrep detected nodal metastasis with an overall sensitivity of 77.5%, specificity of 100%, PPV of 100% and NPV of 53.7%. Diagnostic accuracy was 82.2%. There was no difference in Bloom-Richardson grade or the number or size of metastases between tumours with true-positive and false-negative cytology. Sampling error was the sole factor contributing to cyto-histological discrepancy.
  
  
  CONCLUSIONS
  ThinPrep is a good alternative to the conventional smear for cytological assessment of axillary lymph node status in patients with invasive breast carcinoma, particularly when specimens are collected at remote sites or when cytologists are not available for assistance during FNA.
authors.affiliation: Department of Pathology, University of Michigan, Ann Arbor, MI, USADepartment of Pathology, Beaumont Hospital, Troy, MI, USADepartment of Pathology, Case Western University/University Hospitals Case Medical Center, Cleveland, OH, USA.
authors.forename: X
authors.initials: X
authors.lastname: Jing
authors.forename: E
authors.initials: E
authors.lastname: Wey
authors.forename: C W
authors.initials: CW
authors.lastname: Michael
mesh_terms: D001365:Axilla / Q000473:pathology*; D044963:Biopsy, Fine-Needle / Q000379:methods; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis* / Q000473:pathology*; D003581:Cytodiagnosis; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D011237:Predictive Value of Tests; D021701:Sentinel Lymph Node Biopsy