Thyroid gland
Competency Assessment
1. Thyroid gland and nodules

Topic Completed: 1 November 2013

Revised: 4 January 2018, last major update November 2013

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

Ricardo R. Lastra, M.D.
Michelle R. Pramick, M.D.
Page views in 2018: 1,153
Page views in 2019 to date: 530
Cite this page: Pramick M.R., Baloch Z.W., Lastra R. R. Thyroid nodules. website. Accessed June 17th, 2019.
Normal Anatomy and Cytology
Medical knowledge
  1. Recognize the normal anatomy of thyroid gland and its relationship to other vital structures in the neck
  2. Recognize the normal cellular and noncellular elements visible in a thyroid FNA specimen and their histologic correlates
    • Colloid
    • Macrophages
    • Follicular cells
    • Blood components (red blood cells, inflammatory cells, platelet clumps)
    • Mesenchymal cells
  3. Recognize various forms of normal thyroid follicular cells and their key cytoplasmic and nuclear features
    • Follicular cells
    • Oncocytic follicular cells (AKA Hürthle cells)
  4. Recognize various architectural arrangements of thyroid follicular cells
    • Monolayer sheets
    • Microfollicle
    • Macrofollicle
  5. Identify and recognize the significance of various forms of colloid

Practice based learning
  1. Understand the histologic correlates of various cellular and noncellular components seen in thyroid cytology specimens
  2. Identify the various architectural patterns formed by thyroid cells
  3. Recognize forms of colloid and its patterns seen in smears, monolayer and cell block preparations
  4. Recognize artifacts that might obscure or mimic cellular elements
    • Air drying artifact
    • Platelet clumps vs. follicular cell groups
    • Poor fixation artifact leading to loss of nuclear chromatin details
Cytology images

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Follicular cells, normal thyroid gland

Thyroid Nodule Presentation, Thyroid Function Tests and Key Ultrasound Features
Medical knowledge
  1. Recognize the basic principles of thyroid function tests
  2. Recognize the basic elements of clinical history pertinent to thyroid nodule
    • Duration
    • Stable in size or growth
    • History of thyroid disease
    • Family history of thyroid cancer
    • Exposure to radiation during childhood
    • History of other cancers especially endocrine tumors
  3. Understand the clinical presentation of thyroid nodules
    • Palpable vs. nonpalpable
    • Single vs. multiple
    • Firm vs. soft
    • Fixation to surrounding structures
    • Associated lymphadenopathy
    • Causing swallowing or breathing difficulties
    • Associated hypothyroidism or hyperthyroidism
  4. Recognize the key ultrasound features of thyroid nodules
    • Location
    • Single vs. multiple
    • Solid vs. complex vs. cystic
    • Vascularity
    • Echogenecity
      • Hypoechoic
      • Hyperechoic
      • Isoechoic
    • Presence of absence of halo around nodule
    • Nodule margins
      • Regular
      • Irregular
      • Extrathyroidal extension
    • Calcifications
    • Micro- vs. macrocalcifications
    • The status of surrounding thyroid parenchyma
      • Heterogeneous
      • Nodular
      • Normal - homogeneous

Practice based learning
  1. Understand the importance of clinical history and other significant conditions in the accurate interpretation of the thyroid nodules
  2. Understand the importance of clinical history as related to the risk of malignancy in thyroid nodules
    • Family history of thyroid cancer
    • History of head and neck irradiation
    • Regional lymphadenopathy
  3. Understand how abnormalities in thyroid function can alter cell morphology, colloid and smear background
    • Follicular cell nuclear atypia in hypo- and hyperthyroidism
    • Increase amount of oncocytic follicular cells in chronic lymphocytic thyroiditis, i.e., hypothyroidism
    • Lymphocytes and lymphoid follicles in chronic lymphocytic thyroiditis, i.e., hypothyroidism
    • Lack of watery colloid in chronic lymphocytic thyroiditis
  4. Understand the key differences between manual vs. ultrasound guided FNA
    • Selection of suspicious nodule for fine needle aspiration in multinodular goiter
    • Sample adequacy
    • Targeting solid component in cystic nodule
    • Sampling deep seated thyroid nodules
  5. Understand the key ultrasound features of thyroid nodules
  6. Recognize the suspicious ultrasound features of thyroid nodules
    • Hypoechogenicity
    • Vascularity
    • Microcalcification
    • Irregular margins
    • Presence of halo
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