Thyroid thyrothymic extension: An anatomic study in a surgical series
Related Experiment Video
Updated: Apr 19, 2026
Transoral Robotic Total Thyroidectomy and Bilateral Central Regional Lymph Node Dissection for Papillary Thyroid Carcinoma
Published on: September 15, 2023
Patrick Sheahan1, Fergal O'Duffy1
1Department of Otolaryngology - Head and Neck Surgery, South Infirmary Victoria University Hospital, Cork, Ireland.
Background:
The thyrothymic extension (TTE) is a variable projection from the inferior thyroid pole along the course of the thyrothymic ligament. Awareness of the TTE is critical to ensure complete total thyroidectomy. However, there is little mention of the TTE in the literature. The purpose of the present study was to investigate the frequency of the TTE in our surgical series.
Methods:
We conducted a prospective cohort study of 284 thyroid and parathyroid surgeries performed by a single surgeon.
Results:
A TTE was present in 138 of 414 evaluable thyroid lobes (33.3%), with no predilection for left or right. The TTE was bilateral in 57% of cases. In 5 cases, there was significant nodular enlargement of the TTE. The inferior parathyroid gland was closely associated with 8% of TTEs.
Conclusion:
The TTE is a commonly encountered projection from the inferior thyroid pole. Awareness of the TTE is important to ensure complete total thyroidectomy.
Related Concept Videos
01:23The Thyroid Gland
The follicles have a central cavity lined by simple cuboidal to squamous epithelial cells called follicular cells. These cells produce the glycoprotein...
01:27Hyperthyroidism II: Pathophysiology