Cytopathology
Palpation guided fine needle aspiration
Analysis of FNA procedure and diagnosis




Topic Completed: 1 August 2013

Revised: 3 January 2019, last major update August 2013

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PubMed Search: Analysis of FNA procedure and diagnosis [title]

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Cite this page: Jakowski J. D. Analysis of FNA procedure and diagnosis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cytopathologypgfnaanalysis.html. Accessed April 22nd, 2019.
Definition / general
  • FNA is accepted as:
    • Cost effective
      • Average cost of FNA for diagnosis is $380; average cost for open surgical biopsy for diagnosis is $1831 [2006 data]
      • FNA savings to overall healthcare system, by reducing surgeries, followup visits and additional unnecessary clinical workup is substantial (~$500,000 per 1000 FNAs) [1996 data] (Cancer 2006;107:2270, Cancer 2001;93:319)
    • Accurate for diagnosis, particularly if same physician performs FNA and interprets specimen microscopically (Cancer 2006;107:406, Avicenna J Med 2011;1:18)
  • Most diagnostic failures are due to nondiagnostic samples or to making a diagnosis on inadequate or nonrepresentative sample
  • Factors associated with accuracy, sensitivity, specificity, and unsatisfactory rates include:
    • Tumor type
    • Tumor size
    • Adequacy of sample
    • Training, experience, and technical expertise in performing FNA
    • Sample preparation and processing
    • On site sample adequacy assessment
    • Use of image guidance (Diagn Cytopathol 2013;41:871)
  • Unsatisfactory rate for all FNA sites should be < 10%, but < 5% is the ideal and an achievable goal
  • Reaspiration success rates for a previous mass or lesion with an initial unsatisfactory diagnosis have not been established for most sites, but in thyroid are ~70%
Error rates
  • Error rate documentation in limited for FNAs; for surgical pathology, error rate is 0.26% to 1.2%
  • Second opinion and interinstitutional review of FNA material when patient is referred from outside hospital is prudent and may be required
    • Major diagnostic disagreement, defined as a 2 step difference resulting in a potential change in treatment or prognosis, has been reported in up to 9.3% of FNA cytology cases, with a resulting change in patient evaluation or treatment in up to 5.8% of the cases
    • Diagnosis by board certified cytopathologists rendering the second opinion may be more supported by followup, in contrast to non board certified cytopathologists' review (Adv Anat Pathol 2010;17:437, Diagn Cytopathol 2002;26:45)
Statistical analysis of FNA diagnoses
  • Selected number of peer reviewed articles regarding statistical analysis of FNA diagnoses from common anatomical sites, with particular attention to FNA usefulness in distinguishing benign from malignant diseases:
FNA Site Sensitivity Specificity Accuracy PPV NPV FP FN
Salivary Gland 76 - 83% 93 - 98% 89 - 96% 87 - 90% 94% 0.5 - 6% 0 - 16%
Thyroid 65 - 98% 72 - 100% 75 - 90% 94 - 99% 66 - 97% 0 - 8% 1 - 12%
Breast 73 - 97% 78 - 100% 91 - 93% 92 - 99% 86 - 92% 0.5 - 2% 3 - 5%
Lymph Node (including benign/reactive vs. all types of lymphoma* vs. metastasis) 30 - 97% 67 - 100% 72 - 97% 82 - 99% 81 - 93% 0.9 - 4% 3 - 27%
Bone and Soft Tissue Tumors 79 - 96% 72 - 98% 73 - 95% 67 - 99% 82 - 92% 1 - 5% 2 - 15%

  • PPV: positive predictive value; NPV: negative predictive value; FP: false positive rate; FN: false negative rate
  • Use of ancillary techniques, including immunocytochemistry, flow cytometry, and molecular to diagnose non Hodgkin lymphoma is very useful and can greatly increase sensitivity, specificity, and accuracy of FNA diagnosis
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