Lingual Thyroid Definition, Symptoms, Causes, Treatment

Abnormal development of the thyroid gland during embryonic stages results in the formation of a mass of ectopic thyroid tissue known as a lingual thyroid that can be found at the base of the tongue. The majority of the abnormal tissue can be found in the tongue. Lingual thyroid is basically a birth abnormality characterized by the presence of thyroid tissue at the base of the tongue. 

Development of the thyroid glands commences approximately 24 days after fertilization from a median endodermal thickening on the base of the primitive hypopharynx, which shows as a foramen cecum diverticulum. The developing hyoid bone serves as the thyroid primordium's initial stop before migrating downward to its final location at the lower neck. 

When migration fails, leftover thyroid tissue develops, leading to ectopic thyroid glands. Females are more likely than males to have an ectopic thyroid gland. The lingual region is where it is most frequently found, followed by the prehyoid area and the thyroglossal duct tract. 

Lingual Thyroid Definition

It is a subtype of ectopic thyroid that develops when the thyroid gland fails to properly grow during the embryonic stage, it can cause a lump of ectopic thyroid tissue, known as lingual thyroid.

Lingual Thyroid Symptoms

The majority of thyroid ectopias are clinically undetected and only become apparent when patients are having surgery for another reason. 90% of cases with thyroid ectopia that is clinically recognized are lingual thyroid. 

Although most lingual thyroid patients are asymptomatic, they can exhibit symptoms like coughing, hoarseness, and sleep apnea. Airway blockage is uncommon. Most patients have hypothyroidism. Lingual thyroids that are clinically apparent show up near the base of the tongue as a submucosal, smooth lump.

Lingual Thyroid Causes

When migration fails, leftover thyroid tissue develops, leading to ectopic thyroid glands. This can occur during fetal or early childhood development. Lingual thyroid is more prevalent in females than in males and can develop on either side of the tongue, although the right side is more common. Multiple reasons may contribute to the formation of lingual thyroid, including congenital abnormalities, head and neck injuries, previous surgeries, and radiation therapy.

Lingual Thyroid Treatment

Thyroid hormone therapy is typically used to inhibit and shrink the lingual thyroid in order to address this problem. Surgical excision is rarely required. Extirpation is used when suppressive medication fails to diminish the size, when there is an ulcer or bleeding, or when there is a suspicion of carcinoma. Autotransplantation of thyroid tissue has reportedly proven successful in exceptional cases when no other thyroid tissue is present.