Anatomic Pathology: Thyroid and Parathyroid Gland Pathology

• The thyroglossal duct originates in the foramen caecum of the posterior oral cavity, and extends along the midline to the ultimate position of the thyroid.

• Thyroid-type neoplasms may arise in thyroglossal duct cysts, or in ectopic thyroid tissue, which frequently exists adjacent to thyroglossal duct cysts.

• Papillary carcinoma is the most common thyroid-type neoplasm in this context.

• Medullary carcinoma arises from “C” cells (or their precursors), which migrate into the thyroid from the fourth/fifth branchial pouch.

• The thyroglossal duct does not contain “C” cells, and medullary carcinoma would, therefore, be highly unusual in thyroglossal duct remnants.

Mills SE: Sternberg’s Diagnostic Surgical Pathology, 5th ed. Vol. 1, Chap. 13. Philadelphia: Lippincott Williams & Wilkins, 2009.

Rosai J (ed): Rosai and Ackerman’s Surgical Pathology, 10th ed. Vol. 1, Chap. 9. St. Louis: Mosby, 2004.

* = Required 
* Note Title
* Note