Goiter The 5 Minute Pediatric Consult


	Goiter

Adda Grimberg and Marta Satin-Smith

Database
Differential Diagnosis
Data Gathering
Physical Examination
Laboratory Aids
Therapy
Follow-Up
Common Questions and Answers
Bibliography

DATABASE

DEFINITION

Goiter is enlargement of the thyroid gland.

PATHOPHYSIOLOGY

Multiple causes; see Differential Diagnosis
The most common cause of pediatric goiter in the United States is chronic lymphocytic thyroiditis (CLT).

GENETICS

The multinodular goiter 1 (MNG1) locus was identified on chromosome 14q by linkage analysis in one large Canadian family. This represents only one subgroup.
Autoimmune goiters, such as CLT, occur in children with a genetic predisposition.

EPIDEMIOLOGY

Prevalence of goiter in the United States is 3% to 7%, though the incidence is much higher in regions of iodine deficiency.

COMPLICATIONS

Depending on gland size, goiters can produce a mass effect on midline neck structures. Typically, the child is euthyroid, but clinical hypothyroidism or hyperthyroidism may result from certain types of goiters.

PROGNOSIS

Depends on the cause of the goiter

DIFFERENTIAL DIAGNOSIS

Immunologic
- Chronic lymphocytic thyroiditis (often referred to as Hashimoto thyroiditis)
- Graves disease
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
- Iodine deficiency
Neoplastic
- Thyroid adenoma/carcinoma
- TSH-secreting adenoma
- Lymphoma
Congenital
- Ectopic gland
- Unilateral agenesis of gland
- Dyshormonogenesis
- Thyroxine resistance
Miscellaneous
- Simple colloid goiter
- Multinodular goiter

DATA GATHERING

HISTORY

Symptoms of hypothyroidism or hyperthyroidism
- Hypothyroidism: increase in sedentary behavior, lethargy, weight gain, constipation, cold intolerance, dry skin and/or hair, hair loss
- 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.

PHYSICAL EXAMINATION

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.
- Auscultate with the stethoscope diaphragm (while patient holds his/her breath) for a bruit, which is indicative of the hyperthyroidism-associated hypervascularity.
Pain on palpation suggests acute inflammation.
Careful examination for signs of hypothyroidism or hyperthyroidism: pulse, linear growth and weight pattern, sexual development, deep tendon reflexes, skin

Procedure

Have patient drink water during inspection of gland. Isthmus of thyroid is just below the cricoid cartilage.

LABORATORY AIDS

TESTS

Thyroid function tests: total T4 and TSH comprise the best screen for hypo- or hyper-thyroidism.
T3-RIA in cases of suspected hyperthyroidism (Note: RIA, which measures total T3, and not resin uptake, which indirectly assesses thyroid hormone binding capacity!)
In cases of suspected CLT: antithyroglobulin and antimicrosomal (antiperoxidase) antibodies
In cases of suspected Graves disease:thyroid-stimulating immunoglobulins
Fine-needle aspiration biopsy is not a commonly used procedure in children and should be considered only in the evaluation of low-risk or purely cystic thyroid nodules.

Imaging

Ultrasound is useful in determining the number, size, and nature (cystic, solid, or mixed) of nodules.
I-123 thyroid scans should be done in cases of solitary nodules to establish whether or not the nodule concentrates iodide. “Cold” nodules (no I-uptake) are suggestive of 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

THERAPY

Therapy is dictated by the cause of the goiter. Surgery solely to decrease the size of a goiter is indicated only if adjacent structures are compressed.

DRUGS

L-thyroxine is indicated for the treatment of goiters with hypothyroidism. In cases of goiter with hyperthyroidism, initial treatment consists of antithyroid drugs (propylthiouracil or methimazole). Please see sections on hypothyroidism and Graves disease for further details.

DURATION

Depends on the cause of the goiter

DIET

Depends on the cause of the goiter. The 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.

POSSIBLE CONFLICTS

In the case of 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.

FOLLOW-UP

The potential for goiter regression depends on its cause. Goiters associated with CLT 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.

PITFALLS

Failure to work up solitary thyroid nodules aggressively; remember, incidence of malignancy in these nodules in children is 15% to 40% (less in adults).

COMMON QUESTIONS AND ANSWERS

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 again depends on the cause of the goiter. For example, correction of an elevated TSH in CLT with treatment can result in goiter shrinkage. In iodine-deficient states, treatment will cause the early hyperplastic goiter to regress.

ICD-9-CM 240.9

BIBLIOGRAPHY

Aghini-Lombardi F, Antonangeli Z, Martino E, Vitti P, Maccherini D, Leoli F, Rafo T, et al. The spectrum of thyroid disorders in an iodine-deficient community: The Pescopagamo survey. J. Clin Endocrinol Metab 1999;84:561–566.

Alter CA, Moshang T. Diagnostic dilemma: the goiter. Pediatr Clin North Am 1991;38:567–578.

Bignell GR, Canzian F, Shayeghi M, et al. Familial nontoxic multinodular goiter locus maps to chromosome 14q but does not account for familial nonmedullary thyroid cancer. Am J Hum Genet 1997;61:1123–1130.

Hopwood NJ, Kelch RP. Thyroid masses: approach to diagnosis and management in childhood and adolescence. Pediatr Rev 1993;14:481–487.

Ladenson PW. Optimal laboratory testing for diagnosis and monitoring of thyroid nodules, goiter, and thyroid cancer. Clin Chem 1996;42:183–187.

Wang C, Crapo LM. The epidemiology of thyroid disease and implications for screening. Endocrinol Metab Clin North Am 1997;26:189–218.

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