Thyroid thyrothymic extension: An anatomic study in a surgical series

Head Neck. 2016 May;38(5):732-5. doi: 10.1002/hed.23954. Epub 2015 May 26.


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.

Keywords: anatomy; parathyroid; thymus; thyroid; thyrothymic.

MeSH terms

  • Cohort Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Parathyroid Glands / surgery*
  • Prospective Studies
  • Thymus Gland / anatomy & histology*
  • Thyroid Gland / surgery*
  • Thyroidectomy / statistics & numerical data*