Endocrine: Lingual Thyroid

Lingual Thyroid

Basics

  • Definition: Ectopic Thyroid Tissue at the Base of the Tongue
  • Cause: Abnormal Thyroid Descent
  • More Common in Females (4-7:1)
    • More Commonly Identified When TSH Levels Rise Causing Hypertrophy (Puberty, Pregnancy or Menopause)
  • 70% are Hypothyroid
  • 70% Do Not Have Any Other Functional Thyroid Tissue
  • Malignant Transformation is Rare (1/100)

Presentation

  • Mostly Asymptomatic
  • Dysphagia
  • Dysphonia
  • Sore Throat
  • Bleeding
  • Upper Airway Obstruction

Diagnosis

  • Diagnosis: Radiolabeled Technetium (99m Tc) Scan
  • Other Work-Up: Thyroid Function Tests & US of Neck (Evaluate for Normal Thyroid Tissue)

Treatment

  • Mild Symptoms & Hypothyroidism: Levothyroxine
  • Indications for Surgical Excision:
    • Severe Compressive Symptoms
    • Hemorrhage or Ulceration
    • Uncontrolled Hyperthyroidism
    • Concern for Malignancy
    • Cosmesis
  • If Unfit for Surgery: Radioactive Iodine (RAI)

Lingual Thyroid (Arrow) 1

Lingual Thyroid on 99m Tc Scan 2

References

  1. Dutta D, Kumar M, Thukral A, Biswas D, Jain R, Ghosh S, Mukhopadhyay S, Chowdhury S. Medical management of thyroid ectopia:report of three cases. J Clin Res Pediatr Endocrinol. 2013 Sep 10;5(3):212-5. (License: CC BY-2.5)
  2. Sukumar SP, Balachandran K, Jayakumar, Kamalanathan S, Sahoo JP, Das AK, Halanaik D. Congenital hypothyroidism – An usual suspect at an unusual age: A case series. Indian J Endocrinol Metab. 2013 Oct;17(Suppl 1):S184-7. (License: CC BY-NC-SA-3.0)