Goiter
Goiter: Excerpt from The 5-Minute Pediatric Consult
Adda Grimberg, MD
Goiter - BASICS
Goiter - description
Goiter is enlargement of the thyroid gland.
Goiter - epidemiology
- The most common cause of pediatric goiter in the US is chronic lymphocytic thyroiditis.
- Prevalence of goiter in the US is 3–7%, although the incidence is much higher in regions of iodine deficiency.
- Thyroid cancers comprise 0.5–1.5% of all malignancies in children and adolescents.
- Thyroid tumors and autoimmune thyroid disease are both more common in females than in males.
Goiter - prevalence
World Health Organization (WHO) Global Database on Iodine Deficiency (1993–2003)
- Global goiter prevalence is 15.8% of the general population.
- Insufficient iodine intake among school-aged children ranged 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.
Goiter - etiology
- The multinodular goiter 1 (MNG1) locus has been identified on chromosome 14q and on chromosome Xp22.
- Other genes implicated in simple goiter formation include 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 contribution of environmental factors, especially iodine deficiency and cigarette smoking.
- 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)-2A and -2B, or as isolated malignancy.
- Pendred syndrome (autosomal recessive) causes congenital sensorineural deafness and iodine organification defect that leads to goiter.
Goiter - DIAGNOSIS
Goiter - signs & symptoms
Goiter - history
- Symptoms of hypothyroidism:
- Increase in sedentary behavior
- Lethargy
- Weight gain
- Constipation
- Cold intolerance
- Dry skin and/or hair
- Hair loss
- Symptoms of hyperthyroidism:
- Hyperactivity
- Irritability
- Difficulty concentrating or focusing in school
- Hyperphagia
- Weight loss
- Diarrhea
- Heat intolerance
- Careful dietary and medication history
- History of head, neck, or chest irradiation is associated with increased risk of carcinoma.
- Family history of thyroid carcinoma or MEN syndrome
Goiter - physical exam
Inspect, palpate, and auscultate the neck:
- Neck extension aids inspection.
- Palpation is best performed standing behind the child.
- Determine if the thyroid is diffusely enlarged or asymmetric, evaluate gland firmness, and assess for any nodularity.
- Check for cervical lymphadenopathy.
- Pain on palpation suggests acute inflammation.
- Auscultate with the stethoscope diaphragm (while patient holds his or her breath) for a bruit, which indicates the hyperthyroidism-associated hypervascularity.
- Careful examination for signs of hypothyroidism or hyperthyroidism:
- Pulse
- Linear growth and weight pattern
- Sexual development
- Deep tendon reflexes
- Skin
- Have patient drink water during inspection of gland.
Goiter - tests
- Thyroid function tests: Total TT
- In cases of suspected chronic lymphocytic thyroiditis: Antithyroglobulin and antimicrosomal (antiperoxidase) antibodies
- In cases of suspected Grave disease: Thyroid-stimulating immunoglobulins (or TSH-receptor antibodies)
- Fine-needle aspiration biopsy in children should be considered only for evaluation of low risk or purely cystic thyroid nodules. (A higher percentage of solitary thyroid nodules are malignant in children compared with adults.)
- Calcitonin levels: Elevated in 75% of patients with medullary carcinoma
Goiter - lab
Urinary iodine (UI) concentration is the best measure of the adequacy of iodine intake.
Goiter - imaging
- Ultrasound to determine the number, size, and nature (cystic, solid, or mixed) of nodules
- 123I thyroid scans in cases of solitary nodules to establish whether the nodule concentrates iodide
- “Cold” nodules (no I uptake) suggest neoplasia and require immediate evaluation by a pediatric endocrinologist and surgeon.
- Barium swallow studies can reveal a fistulous tract between the left piriform sinus and the left thyroid lobe in children with recurrent acute suppurative thyroiditis. Such fistulas are amenable to surgical resection.
False positives:
- Fat neck: Adipose tissue, large sternocleidomastoid muscles
- Thyroglossal duct cysts
- Nonthyroidal neoplasms: Lymphoma, teratoma, hygroma, ganglioneuroma
Goiter - differencial diagnosis
- Immunologic:
- Chronic lymphocytic thyroiditis (often referred to as Hashimoto thyroiditis)
- Graves disease
- Amyloid deposition (familial Mediterranean fever, juvenile rheumatoid arthritis)
- Infectious:
- Acute suppurative thyroiditis (most often Streptococcus pyogenes, Staphylococcus aureus, and Streptococcus pneumoniae)
- Subacute thyroiditis (often viral)
- Environmental:
- Goitrogens: Iodide, lithium, amiodarone, oral contraceptives, perchlorate, cabbage, soybeans, cassava, thiocyanate in tobacco smoke (smoking is especially goitrogenic in iodine-deficient areas)
- Iodine deficiency (exacerbated by pregnancy)
- Neoplastic:
- Thyroid adenoma/carcinoma
- Follicular adenoma: Benign
- Follicular, papillary, or mixed carcinoma: Well differentiated; follicular 90%
- Medullary carcinoma: 4–10% as part of the MEN, type 2 syndrome
- TSH-secreting adenoma
- Lymphoma
- Congenital:
- Ectopic gland
- Unilateral agenesis of gland
- Dyshormonogenesis
- Thyroxine resistance
- Miscellaneous:
- Simple colloid goiter
- Multinodular goiter
Goiter - TREATMENT
Possible conflicts: In manic-depressive patients on lithium and cardiac patients on amiodarone, medication-induced thyroid abnormalities can be a significant problem that should be addressed by the endocrinologist and appropriate subspecialist.
Goiter - general measures
Goiter - diet
- Depends on the cause of the goiter
- Incidence of iodine deficiency (endemic) goiter has greatly declined since the addition of potassium iodide to table salt.
- Iodide can also be added to communal drinking water or administered as an iodized oil in isolated rural areas.
Goiter - special therapy
Intra-amniotic injections of l-thyroxine may treat fetal goitrous hypothyroidism. Large fetal goiters pose a risk of airway compromise at birth.
Goiter - medication
- Goiters with hypothyroidism: L-thyroxine
- Goiter with hyperthyroidism: Initial treatment consists of antithyroid drugs (propylthiouracil or methimazole).
- Duration depends on the cause of the goiter.
Goiter - surgery
Surgery solely to decrease the size of a goiter is indicated only if adjacent structures are compressed. Cancer:
- Surgery is recommended for a nonfunctioning nodule if there is:
- A history of radiation
- Rapid growth of a firm nodule
- Evidence of satellite lymph nodes
- Evidence of impingement on other neck structures
- Evidence of distant metastases
- The affected lobe is removed and sent for frozen section; if this is suspicious, a total thyroidectomy should be performed.
- Following surgery, therapy is administered if a follow-up iodine scan reveals any residual tissue or metastases.
- Suppressive doses of exogenous thyroid hormone are then given to maintain TSH levels <0.2 μIU/mL.
- Thyroglobulin levels are useful as markers of thyroid tissue; calcitonin level serves as tumor marker for medullary carcinoma.
- Some advocate subtotal thyroidectomy, no irradiation, and suppressive T
Goiter - FOLLOW UP
- Potential for goiter regression depends on its cause. Goiters associated with chronic lymphocytic thyroiditis and Graves disease may or may not decrease in size with treatment.
- A goiter patient who is clinically and biochemically euthyroid still requires careful follow-up for the detection of the early signs of developing thyroid dysfunction.
- Potential complications of thyroid surgery include laryngeal nerve damage and hypoparathyroidism.
Workup solitary thyroid nodules aggressively; remember, incidence of malignancy in these nodules in children is 15–40% (less in adults).
Goiter - prognosis
- Depends on the cause of the goiter
- Thyroid cancers usually follow an indolent course with excellent prognosis, especially the well-differentiated follicular cell carcinoma. Mortality is most common in medullary and undifferentiated carcinomas, which are relatively rare in children.
Goiter - complications
- Depending on gland size, goiters can produce a mass effect on midline neck structures. If the goiter is intrathoracic, it may cause pleural effusions or chylothorax.
- Typically, the child is euthyroid, but clinical hypothyroidism or hyperthyroidism may result from certain types of goiters.
- Therapy for thyroid cancer may induce permanent hypothyroidism.
Goiter - bibliography
- American Academy of Pediatrics Committee on Environmental Health. Risk of ionizing radiation exposure to children: A subject review. Pediatrics. 1998;101:717–719.
- Andersson M, Takkouche B, Egli I, et al. Current global iodine status and progress over the last decade towards the elimination of iodine deficiency. Bull World Health Organ. 2005;83:518–525.
- Capon F, Tacconelli A, Giardina E, et al. Mapping of a dominant form of multinodular goiter to chromosome Xp22. Am J Hum Genet. 2000;67:1004–1007.
- From G, Mellemgaard A, Knudson N, et al. Review of thyroid cancer cases among patients with previous benign thyroid disorders. Thyroid. 2000;10:697–700.
- Hashimoto H, Hashimoto K, Suehara N. Successful in utero treatment of fetal goitrous hypothyroidism: Case report and review of the literature. Fetal Diagn Ther. 2006;21:360–365.
- Hegedus L, Bonnema SJ, Bennedbaek FN. Management of simple nodular goiter: Current status and future perspectives. Endocr Rev. 2003;24:102–132.
- Knudsen N, Laurberg P, Perrild H, et al. Risk factors for goiter and thyroid nodules. Thyroid. 2002;12:879–888.
- Nath CA, Oyelese Y, Yeo L, et al. Three-dimensional sonography in the evaluation and management of fetal goiter. Ultrasound Obstet Gynecol. 2005;25:312–314.
- Niedziela M. Pathogenesis, diagnosis and management of thyroid nodules in children. Endocr Relat Cancer. 2006;13:427–453.
- Pfarr N, Borck G, Turk A, et al. Goitrous congenital hypothyroidism and hearing impairment associated with mutations in the TPO and SLC26A4/PDS genes. J Clin Endocrinol Metab. 2006;91:2678–2681.
- Rios A, Rodriguez JM, Canteras M, et al. Risk factors for malignancy in multinodular goitres. Eur J Surg Oncol. 2004;30:58–62.
- Yeh SD, La Quaglia MP. 131I therapy for pediatric thyroid cancer. Semin Pediatr Surg. 1997;6:128–133.
- Zimmermann MB, Hess SY, Molinari L, et al. New reference values for thyroid volume by ultrasound in iodine-sufficient schoolchildren: A World Health Organization/Nutrition for Health and Development Iodine Deficiency Study Group Report. Am J Clin Nutr. 2004;79:231–237.
- Zimmermann MB, Ito Y, Hess SY, et al. High thyroid volume in children with excess dietary iodine intakes. Am J Clin Nutr. 2005;81:840–844.
Goiter - CODES
Goiter - icd9
240.9 Goiter
Goiter - FAQ
- Q: Does a bigger thyroid gland mean increased thyroid functioning?
- A: Goiters can be euthyroid, hypothyroid, or hyperthyroid, depending on cause.
- Q: Will the goiter decrease in size with treatment?
- A: This depends on the cause of the goiter. For example, correction of an elevated TSH in chronic lymphocytic thyroiditis with treatment can result in goiter shrinkage. In iodine-deficient states, treatment will cause the early hyperplastic goiter to regress.
- Q: Does a bigger thyroid gland mean cancer?
- A: Most pediatric goiters are benign, and thyroid cancers often are detected as solitary nodules within an otherwise normal gland (in children with solitary nodules, up to 40% are carcinomas). Patients with a history of goiter or benign nodules/adenomas have an increased risk of developing thyroid cancer.
- Q: Does thyroid cancer usually present with hyperthyroidism?
- A: No. The usual chief complaint is a solitary, hard, painless nodule in a euthyroid patient.
- Q: Is there an increased risk of thyroid cancer from diagnostic radiographs (chest radiographs, lateral neck films)?
- A: Routine diagnostic radiographs should fall well below the levels of radiation thought to increase risk of thyroid neoplasia. During more prolonged radiologic procedures that might expose the thyroid to higher doses of radiation, a lead neck shield is used.
- Q: Should prophylactic thyroidectomy be performed in children identified genetically as having familial medullary carcinoma?
- A: Yes, because of the poorer prognosis associated with development of this cancer.
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Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
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