Congenital goiter is a diffuse or nodular enlargement of the thyroid gland present at birth. Thyroid hormone secretion may be decreased, increased, or normal. Diagnosis is made by confirming thyroid size with ultrasound. Treatment is thyroid hormone replacement when hypothyroidism is present. Surgery is indicated when breathing or swallowing is impaired.
Etiology of Congenital Goiter
Congenital goiter may be caused by dyshormonogenesis (abnormal thyroid hormone production), transplacental passage of maternal antibodies, or transplacental passage of goitrogens. Some causes of congenital goiter are hereditary. (See also Simple Nontoxic Goiter in adults and Overview of Thyroid Function.)
Dyshormonogenesis
Genetic defects in thyroid hormone production result in increased levels of thyroid-stimulating hormone (TSH), which in turn can cause congenital goiter. Goiter is present in the minority of cases of congenital hypothyroidism. There are a number of gene abnormalities that cause dyshormonogenesis (eg, DUOX2, TG, TPO, SLC5A5); they commonly have an autosomal recessive form of inheritance and many are single-gene defects (1, 2).
Dyshormonogenesis can result from a defect in any of the steps in thyroid hormone biosynthesis, including:
Failure to concentrate iodide
Defective organification of iodide due to an abnormality in the thyroid peroxidase enzyme or in the hydrogen peroxide–generating system
Defective thyroglobulin synthesis or transport
Abnormal iodotyrosine deiodinase activity
Children with Pendred syndrome have mild hypothyroidism or euthyroidism, goiter, and sensorineural hearing loss due to a genetic abnormality of a protein (pendrin) involved in iodine transport and cochlear function. Although Pendred syndrome is caused by a genetic defect, it rarely manifests in the newborn period (3).
Transplacental passage of maternal antibodies
Pregnant patients with an autoimmune thyroid disorder produce antibodies that may cross the placenta during the third trimester. Depending on the disorder, the antibodies either block thyroid-stimulating hormone receptors, causing hypothyroidism, or stimulate them, causing hyperthyroidism (neonatal Graves disease).
Typically, in affected infants, the changes in hormone secretion and the associated goiter resolve spontaneously after 3 or more months (4).
Transplacental passage of goitrogens
Goitrogens, such as amiodarone, iodine, or antithyroid medications (eg, propylthiouracil, methimazole), taken by the mother can cross the placenta, sometimes causing hypothyroidism and rarely causing goiter.
Etiology references
1. Rose SR, Wassner AJ, Wintergerst KA, et al: Congenital Hypothyroidism: Screening and Management. Pediatrics 151(1):e2022060419, 2023. doi: 10.1542/peds.2022-060419
2. Persani L, Rurale G, de Filippis T, Galazzi E, Muzza M, Fugazzola L: Genetics and management of congenital hypothyroidism. Best Pract Res Clin Endocrinol Metab 32(4):387-396, 2018. doi: 10.1016/j.beem.2018.05.002
3. Li YL, Gong FY, Dang ZY, et al. Analysis of clinical characteristics of thyroid phenotype in Pendred syndrome based on multiple databases. Eur Rev Med Pharmacol Sci. 2023;27(12):5390-5396. doi:10.26355/eurrev_202306_32773
4. Alexander EK, Pearce EN, Brent GA, et al. 2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum. Thyroid. 2017;27(3):315-389. doi:10.1089/thy.2016.0457
Symptoms and Signs of Congenital Goiter
The most common manifestation of congenital goiter is firm, symmetric, nontender enlargement of the thyroid. Enlargement is most often diffuse but can be nodular. It may be noticeable at birth or detected later. In some patients, enlargement is not directly observable, but continued growth can cause deviation or compression of the trachea, compromising breathing and swallowing.
Many children with goiters are euthyroid (1), but some present with hypothyroidism or hyperthyroidism.
Symptoms and signs reference
1. Kim SY, Lee YA, Jung HW, et al. Pediatric Goiter: Can Thyroid Disorders Be Predicted at Diagnosis and in Follow-Up?. J Pediatr. 2016;170:253-9.e92. doi:10.1016/j.jpeds.2015.11.008
Diagnosis of Congenital Goiter
Ultrasound
Thyroid function tests (thyroid stimulating hormone [TSH] and thyroxine [T4])
Sometimes triiodothyronine (T3), TSH receptor antibodies, or genetic testing
If the diagnosis of congenital goiter is suspected, thyroid size is typically assessed by ultrasound.
Free T4 and TSH levels are measured. If there is clinical suspicion of hyperthyroidism, T3 should also be measured and, if the child is hyperthyroid, antibodies against the TSH receptor should be measured (see Hyperthyroidism in Infants and Children).
In cases of suspected dyshormonogenesis, genetic testing may be considered to establish cause because people who have one affected child are at increased risk of having others.
Treatment of Congenital Goiter
Sometimes thyroid hormone
Surgical treatment of enlargement causing symptoms related to compression
Hypothyroidism is treated with thyroid hormone (see Treatment of Hypothyroidism).
Goiters that compromise breathing and swallowing are uncommon but can be treated surgically.
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