Table of Contents
Normal Anatomy and Cytology | Cytology images | Thyroid Nodule Presentation, Thyroid Function Tests and Key Ultrasound FeaturesCite this page: Pramick M.R., Baloch Z.W., Lastra R. R. Thyroid nodules. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/thyroidcompnormalgland.html. Accessed February 21st, 2019.
Normal Anatomy and Cytology
Medical knowledge
Practice based learning
- Recognize the normal anatomy of thyroid gland and its relationship to other vital structures in the neck
- 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
- Recognize various forms of normal thyroid follicular cells and their key cytoplasmic and nuclear features
- Follicular cells
- Oncocytic follicular cells (AKA Hürthle cells)
- Recognize various architectural arrangements of thyroid follicular cells
- Monolayer sheets
- Microfollicle
- Macrofollicle
- Identify and recognize the significance of various forms of colloid
Practice based learning
- Understand the histologic correlates of various cellular and noncellular components seen in thyroid cytology specimens
- Identify the various architectural patterns formed by thyroid cells
- Recognize forms of colloid and its patterns seen in smears, monolayer and cell block preparations
- 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
Thyroid Nodule Presentation, Thyroid Function Tests and Key Ultrasound Features
Medical knowledge
Practice based learning
- Recognize the basic principles of thyroid function tests
- 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
- 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
- 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
- Understand the importance of clinical history and other significant conditions in the accurate interpretation of the thyroid nodules
- 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
- 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
- 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
- Understand the key ultrasound features of thyroid nodules
- Recognize the suspicious ultrasound features of thyroid nodules
- Hypoechogenicity
- Vascularity
- Microcalcification
- Irregular margins
- Presence of halo