Ectopic Thyroid Gland

Objectives: Literature review for thyroid gland ectopy and report two new cases of lingual ectopic thyroid gland.

Methods: English language literature review, 2000-2019 using PUBMED, Medline and online radiology sites.
Case Presentation: Two female patients, 26 and 31 year-old with lingual ectopic thyroid with an intra oral approach for surgery.

Results: Ectopic thyroid tissue is the result of abnormal migration of the thyroid from the floor of the primitive foregut to pretracheal position
This entity is rare, reported in 1 per 100,000- 300,000 population, with a female predilection. Clinical presentation varies according to location and function, with hypothyroidism in one-third of patients.
Ectopic thyroids are found in their majority (80-98%)in the midline of the head/neck, 80 – 90% of which is located in the tongue, 5 -15% in the thyroglossal duct cyst, 1 - 3% in the lateral neck, 1% in the aerodigestive tract 1% and <1% in thorax / abdomen .
Many patients are asymptomatic, with incidental finding during tongue or thyroid imaging. In symptomatic patients, dysphagia, bleeding, or airway obstruction may occur.
Scintigraphy confirms the diagnosis. Ultrasound, MRI or CT can aid to precisely locate the lesion. FNAB may not be diagnostic and cannot completely rule out malignancy. Thyroid function tests are either normal (majority of patients) or demonstrate variable states of hypothyroidism (up to 1/3 of patients).
The advantage of surgical excision is to rule out metastatic thyroid cancer. No treatment is required in asymptomatic cases with normal thyroid function and cytology. An intraoral approach for lingual thyroid is described. The operative time was 90 - 120 minutes and the patients remained free of disease for 18 und 24 months until today.

Conclusions: Ectopic thyroid tissue is relatively uncommon and is characterized by the aggregation of thyroid tissue.
The surgical removal of ectopic thyroid tissue is accomplished by different methods and depends on the localisation of the ectopic tissu and the symptoms.
The tumor in the 2 presented cases was completely resected from intraoral with favorable outcome and relief of symptoms.