Lingual thyroid ectopia

Abstract

The lingual thyroid gland is an abnormal mass of ectopic thyroid tissue visible at the base of the tongue, caused by an embryological anomaly in the development of the thyroid gland. Identification and symptom-adapted treatment of ectopia are important in preventing hypothyroidism and development of obstructive symptoms. Purpose. To present a case of lingual ectopia of the thyroid gland in a child with an incidentally diagnosed formation of the root of the tongue based on primary ultrasound diagnosis. Material and methods. A 7-year-old boy without clinical signs of hypothyroidism during a routine examination revealed a voluminous asymptomatic formation of the root of the tongue. Results. Along the midline at the root of the tongue there is a rounded, non-displaced, painless formation about 20 mm in diameter. Regional lymph nodes are not enlarged. The picture of ectopic thyroid tissue in the root of the tongue, in the absence of thyroid in a typical site on the neck. There is subclinical hypothyroidism with a TSH level of 12.8 mсME/mL (normal 0.6–4.84). The presence of ectopia was confirmed by scintigraphy with Technetium-99m pertechnetate. Normal TSH level of 3.37 mcME/mL and a reduction in the volume of ectopic thyroid tissue from 3.3 mL to 2.13 ml revealed 3 months after levothyroxine therapy at a dose of 50 mcg/day. Conclusion. Ultrasound exam with Doppler mapping is mandatory and allows not only to identify ectopic tissue, but also to identify the absence of thyroid in a typical anatomical area on the neck. The study of the hormonal profile and subsequent scintigraphy make it possible to make a final diagnosis, assess the function of the ectopic organ and determine the option of drug and/or surgical treatment.