A 20-year-old patient presents with a mass at the base of the tongue and no other symptoms. What is the most likely diagnosis?

The most likely diagnosis in this case is a lingual thyroid. A lingual thyroid occurs when thyroid tissue is located at the base of the tongue, which can happen if the thyroid fails to descend properly during embryonic development. This condition can present as a mass at the base of the tongue, particularly in young adults, and is often discovered incidentally or during an examination for an unrelated issue.

In this scenario, the patient's age and the presentation of a solitary mass at the base of the tongue align well with the characteristics of a lingual thyroid. Other conditions might present differently:

Thyroid carcinoma, while possible, would typically show more symptoms, such as changes in voice or swallowing difficulties, and is less common in young adults without a history of thyroid disease.

A thyroglossal duct cyst generally occurs in children and is typically located midline of the neck, not at the base of the tongue. It may present with neck swelling, especially with infection, but does not match the location or profile of the mass in this patient.

Hashimoto's thyroiditis, an autoimmune condition leading to hypothyroidism, generally does not present as a solitary mass at the base of the tongue. It typically manifests with diffuse thyroid enlargement or symptoms related to thyroid