Thyroid gland
Competency Assessment
4. Thyroid fine needle aspiration specimen diagnosis

Author: Ricardo R. Lastra, M.D., Michelle R. Pramick, M.D., Zubair W. Baloch, M.D. (see Authors page)

Revised: 20 January 2017, last major update November 2013

Copyright: (c) 2013-2017, PathologyOutlines.com, Inc.

Table of Contents
Classification Scheme
Cite this page: Fine needle aspiration specimen diagnosis. PathologyOutlines.com website. http://pathologyoutlines.com/topic/thyroidcompfineneedlediagnosis.html. Accessed May 28th, 2017.
Classification Scheme
Medical knowledge
  1. Understand the recommended diagnostic categories of the Bethesda System for reporting thyroid cytopathology
    • Nondiagnostic or unsatisfactory
      • Cyst fluid only
      • Virtually acellular specimen
      • Other (obscuring blood, clotting artifact, etc.)
    • Benign
      • Consistent with a benign follicular nodule (includes adenomatoid nodule, colloid nodule, etc.)
      • Consistent with lymphocytic (Hashimoto) thyroiditis in the proper clinical context
      • Consistent with granulomatous (subacute) thyroiditis
      • Other
    • Atypia of undetermined significance or follicular lesion of undetermined significance
    • Follicular neoplasm or suspicious for a follicular neoplasm
      • Specify if Hürthle cell (oncocytic) type
    • Suspicious for malignancy
      • Suspicious for papillary carcinoma
      • Suspicious for medullary carcinoma
      • Suspicious for metastatic carcinoma
      • Suspicious for lymphoma
      • Other
    • Malignant
      • Papillary thyroid carcinoma
      • Poorly differentiated carcinoma
      • Medullary thyroid carcinoma
      • Undifferentiated (anaplastic) carcinoma
      • Squamous cell carcinoma
      • Carcinoma with mixed features (specify)
      • Metastatic carcinoma
      • Non-Hodgkin lymphoma
      • Other

Practice based learning
  1. Understand the implied risk of malignancy for each diagnostic category of the Bethesda System for reporting thyroid cytopathology
    • Nondiagnostic or unsatisfactory: 1 - 4%
    • Benign: 0 - 3%
    • Atypia of undetermined significance or follicular lesion of undetermined significance: ~5 - 15%
    • Follicular neoplasm or suspicious for a follicular neoplasm: 15 - 30%
    • Suspicious for malignancy: 60 - 75%
    • Malignant: 97 - 99%
  2. Understand the recommended clinical management for each diagnostic category of the Bethesda System for reporting thyroid cytopathology
    • Nondiagnostic or unsatisfactory: repeat FNA with ultrasound guidance
    • Benign: clinical followup
    • Atypia of undetermined significance or follicular lesion of undetermined significance: repeat FNA
    • Follicular neoplasm or suspicious for a follicular neoplasm: surgical lobectomy
    • Suspicious for malignancy: near total thyroidectomy or surgical lobectomy
    • Malignant
    • Near total thyroidectomy