Table of Contents
Definition / general | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Differential diagnosisCite this page: Islam S. Macrofollicular. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/thyroidmacrofollicular.html. Accessed December 20th, 2024.
Definition / general
- Macrofollicles (large dilated follicles) > 50% of cross sectional area, with papillary nuclear features
- Very rare; similar clinical features as classic papillary carcinoma (female predominant, occasional nodal metastases, few deaths)
- May have minor (< 5%) insular component that does not appear to affect prognosis (Cancer 1997;80:1110)
Gross description
- Mean 3 cm, often encapsulated
Microscopic (histologic) description
- Frequent macrofollicles (> 50% of cross sectional area) and foci of follicular variant of papillary carcinoma, all with prominent, large ground glass nuclei and nuclear grooves (Hum Pathol 1991;22:1195)
- Also cells with large but less pale nuclei with stippled chromatin, or cuboidal cells with hyperchromatic nuclei
Microscopic (histologic) images
Cytology description
- Moderate to highly cellular with micro- and macrofollicles with thick colloid
- Papillary nuclear changes often absent or focal
- May resemble goiter (Diagn Cytopathol 2007;35:560, Cancer 1998;84:235)
Differential diagnosis
- Follicular adenoma: lined by flat epithelial cells with hyperchromatic nuclei
- Nodular hyperplasia