Summary about Disease
Lingual thyroid is a rare congenital anomaly where thyroid tissue is located at the base of the tongue instead of its normal position in the neck. It results from the failure of the thyroid gland to descend properly during embryonic development. The lingual thyroid may be the only functioning thyroid tissue in the body for some individuals.
Symptoms
Symptoms can vary greatly depending on the size and functionality of the lingual thyroid. Some individuals may be asymptomatic, while others may experience:
Difficulty swallowing (dysphagia)
Difficulty speaking (dysarthria)
A sensation of a lump in the throat
Choking or gagging
Difficulty breathing (dyspnea), especially if the mass is large
Hypothyroidism symptoms (if the lingual thyroid doesn't produce enough thyroid hormone): fatigue, weight gain, constipation, dry skin, cold intolerance
Bleeding from the mouth
Causes
The primary cause of lingual thyroid is the failure of the thyroid gland to descend from its origin at the base of the tongue to its normal position in the neck during fetal development. The exact reasons for this failure are not fully understood, but genetic factors and environmental influences during pregnancy are suspected to play a role.
Medicine Used
The primary medication used to treat lingual thyroid is:
Levothyroxine (Synthetic T4): This is used to supplement or replace thyroid hormone if the lingual thyroid is not producing enough. It can also help shrink the lingual thyroid tissue by suppressing TSH (thyroid-stimulating hormone) secretion. Other medications may be used to manage specific symptoms, but levothyroxine is the cornerstone of medical management. In some cases radioactive iodine may be used to reduce the size of the thyroid.
Is Communicable
No, lingual thyroid is not a communicable disease. It is a congenital anomaly, meaning it is present at birth due to developmental issues and cannot be transmitted from person to person.
Precautions
Since it is congenital, there are no specific precautions to prevent lingual thyroid. However, women planning pregnancy who have a family history of thyroid disorders should consult with their doctor for preconception counseling. Genetic counseling is also recommended if you or your partner have had a prior diagnosis.
How long does an outbreak last?
Lingual thyroid is not an infectious disease, so it does not have outbreaks. It is a persistent condition that is present from birth. The symptoms, and therefore the need for treatment, can last a lifetime if the lingual thyroid remains.
How is it diagnosed?
Diagnosis typically involves:
Physical Examination: A doctor will examine the base of the tongue and neck.
Thyroid Function Tests: Blood tests to measure TSH, T4, and T3 levels to assess thyroid function.
Thyroid Scan (Radioiodine Scan): A radioactive iodine uptake scan can confirm the presence of thyroid tissue at the base of the tongue and determine if there is thyroid tissue in the normal location.
Ultrasound: To further examine the oral cavity.
CT Scan or MRI: To evaluate the size and location of the lingual thyroid and rule out other causes of a mass in the area.
Biopsy: In some cases, a biopsy may be performed to confirm the diagnosis and rule out malignancy.
Timeline of Symptoms
Lingual thyroid is present at birth, but symptoms may not appear until later in life. The timing of symptom onset can vary:
Infancy/Childhood: Symptoms like difficulty swallowing, breathing problems, or a visible mass in the mouth may be noticed early.
Puberty/Adulthood: Hormonal changes during puberty or pregnancy can sometimes cause the lingual thyroid to enlarge, leading to the onset of symptoms.
Adulthood/Later Life: Some individuals may remain asymptomatic for many years, and the condition may only be discovered incidentally during an examination for another reason.
Important Considerations
Ectopic Tissue: It's crucial to determine if the lingual thyroid is the only functioning thyroid tissue. Removing it without confirming the presence of thyroid tissue in the normal location can lead to permanent hypothyroidism.
Hypothyroidism Risk: Monitor thyroid function regularly, as hypothyroidism can develop or worsen over time.
Pregnancy: Pregnancy can significantly impact thyroid hormone requirements, so close monitoring is essential for women with lingual thyroid.
Malignancy Risk: While rare, lingual thyroid can undergo malignant transformation. Regular monitoring and prompt evaluation of any changes in the size or characteristics of the lingual thyroid are important.
Surgical removal: Surgery is considered if the thyroid causes issues.