Goiter is enlargement of the thyroid gland.


  • The most common cause of pediatric goiter in the United States is chronic lymphocytic thyroiditis.
  • The prevalence of goiter in the United States is 3–7%, although the incidence is much higher in regions of iodine deficiency.
  • Thyroid cancers make up 0.5–1.5% of all malignancies in children and adolescents.
  • Both thyroid tumors and autoimmune thyroid disease are more common in females than males.


World Health Organization (WHO) Global Database on Iodine Deficiency (1993–2003)

  • Goiter prevalence globally is 15.8% of the general population.
  • Insufficient iodine intake among school-aged children ranges from 10.1% in the Americas to 59.9% in Europe.
  • 54 countries had iodine deficiency, 29 countries had excessive iodine intake, and 43 countries achieved optimal iodine intake.


  • Multinodular goiter (MNG) loci have been identified on chromosome 14q and on chromosome Xp22 and 3q26.
  • Germline mutations in DICER1 (chromosome 14q31) have been found in familial MNG-1, with and without ovarian Sertoli-Leydig cell tumors.
  • Germline mutation in thyroid transcription factor-1 (TITF-1/NKX2.1) has been found in patients with papillary thyroid carcinoma and a history of multinodular goiter.
  • Other genes implicated in simple goiter formation: thyroglobulin, thyroid-stimulating hormone (TSH) receptor, and Na+/I symporter
  • Thyroid peroxidase mutations lead to iodide organification defects and goitrous congenital hypothyroidism.
  • Twin and family studies show a modest to major effect of environmental factors, especially iodine deficiency and cigarette smoking.
  • Excessive maternal ingestion of iodine during pregnancy can lead to congenital goiter with increased iodine uptake on scan and in some babies, a transient hypothyroidism.
  • Autoimmune goiters, such as chronic lymphocytic thyroiditis, occur in children with a genetic predisposition.
  • Thyroid cancers are usually sporadic. Medullary carcinoma can be familial (autosomal dominant), as part of multiple endocrine neoplasia (MEN) type 2A and 2B, or as isolated malignancy.
  • Pendred syndrome (autosomal recessive) causes congenital sensorineural deafness and an iodine organification defect that leads to goiter.

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