Diffuse Toxic Goiter Workup

  • Author: Bernard Corenblum, MD, FRCP(C); Chief Editor: George T Griffing, MD   more...
 
Updated: Jul 25, 2011
 

Laboratory Studies

  • If hyperthyroidism due to diffuse toxic goiter is suspected after history and physical examination, the following should be performed:
    • Serum TSH (sensitive or third-generation assay): Levels suppressed below normal indicate the need for more tests. Normal serum TSH level rules out this diagnosis.
    • Serum free thyroxin (T4), or equivalent test, that compensates for any changes in thyroid-binding globulin. If levels are elevated, then hyperthyroidism is diagnosed. Levels will be in the normal range in about 5% of cases.
    • If free thyroxin is normal, then obtain total or free serum triiodothyronine (T3) level. If levels are elevated, then hyperthyroidism is diagnosed. If levels are normal, then subclinical hyperthyroidism is present.
    • The presence of ophthalmopathy indicates the diagnosis, and no more diagnostic testing is needed regarding the cause of the hyperthyroidism.
    • Serum anti-TSH receptor antibodies measurements can be obtained. These antibodies are present in more than 90% of cases of diffuse toxic goiter, depending on the assay.
    • An alternative test is radioiodine uptake. It will separate diffuse toxic goiter (elevated or normal uptake) from the hyperthyroid phase of thyroiditis (suppressed uptake). If the hyperthyroid symptoms have been present for more than 4 months, then thyroiditis is not the cause. This test is contraindicated in women who are pregnant or breastfeeding.
    • An elevated or normal uptake may be found with a single nodular goiter and a multinodular goiter. These may be separated from diffuse toxic goiter by the absence of anti-TSH receptor antibodies, clinical examination, or thyroid scan (technetium-99m or I-123) or ultrasonography.
    • Concomitant presence of Hashimoto thyroiditis may be detected by serum antithyroid antibodies (anti-TPO or thyroperoxidase).
    • If confirmation of oculopathy is needed, then orbital CT or MRI may be performed.
  • Diffuse toxic goiter would have a suppressed serum TSH level, elevated serum free thyroxin level (or T3 if needed), elevated titer of anti-TSH receptor antibodies, or elevated radioiodine uptake. No further testing is needed.
  • Consideration of complications: ECG should be performed if arrhythmia is suspected; liver function tests may be indicated.
  • Consideration of associated disorders: If clinical suspicion, screen for adrenal insufficiency, type 1 diabetes, gonadal failure, other autoimmune disease (eg, pernicious anemia, rheumatoid arthritis, immune thrombocytopenic purpura). Concomitant Hashimoto thyroiditis may have an effect on spontaneous resolution or progression to a hypothyroid state.
  • Drugs that may alter T4 laboratory results include anabolic steroids, androgens, estrogens, heparin, iodine, phenytoin, rifampin, salicylates, and thyroxine/triiodothyronine.
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Contributor Information and Disclosures
Author

Bernard Corenblum, MD, FRCP(C)  Professor of Medicine, Director, Endocrine-Metabolic Testing and Treatment Unit, Ovulation Induction Program, Department of Internal Medicine, Division of Endocrinology, University of Calgary, Canada

Disclosure: Nothing to disclose.

Coauthor(s)

Oluyinka S Adediji, MD  Consulting Staff, Department of Adult and General Medicine, Health Services Incorporated, Montgomery, Alabama

Oluyinka S Adediji, MD is a member of the following medical societies: American College of Physicians and American Medical Association

Disclosure: Nothing to disclose.

Paul Killian, MD  Former Chief of Endocrine Service, Former Associate Professor, Department of Internal Medicine, Harlem Hospital, Harlem Hospital Center

Paul Killian, MD is a member of the following medical societies: American College of Physicians-American Society of Internal Medicine, American Diabetes Association, and Endocrine Society

Disclosure: Nothing to disclose.

Specialty Editor Board

Steven R Gambert, MD  Professor of Medicine, Johns Hopkins University School of Medicine; Director of Geriatric Medicine, University of Maryland Medical Center and R. Adams Cowley Shock Trauma Center

Steven R Gambert, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physician Executives, American College of Physicians, American Geriatrics Society, Association of Professors of Medicine, Endocrine Society, and Gerontological Society of America

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD  Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Yoram Shenker, MD  Chief of Endocrinology Section, Veterans Affairs Medical Center of Madison; Interim Chief, Associate Professor, Department of Internal Medicine, Section of Endocrinology, Diabetes and Metabolism, University of Wisconsin at Madison

Yoram Shenker, MD is a member of the following medical societies: American Heart Association, Central Society for Clinical Research, and Endocrine Society

Disclosure: Nothing to disclose.

Mark Cooper, MBBS, PhD, FRACP  Head, Diabetes & Metabolism Division, Baker Heart Research Institute, Professor of Medicine, Monash University

Disclosure: Nothing to disclose.

Chief Editor

George T Griffing, MD  Professor of Medicine, St Louis University School of Medicine

George T Griffing, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Medical Practice Executives, American College of Physician Executives, American College of Physicians, American Diabetes Association, American Federation for Medical Research, American Heart Association, Central Society for Clinical Research, Endocrine Society, International Society for Clinical Densitometry, and Southern Society for Clinical Investigation

Disclosure: Nothing to disclose.

References

  1. Bahn RS, Burch HB, Cooper DS, et al. Hyperthyroidism and other Causes of Thyrotoxicosis: Management Guidelines of the American Thyroid Association and American Association of Clinical Endocrinoloigists. Endocr Pract. May-Jun 2011;17(3):456-520. [Medline].

  2. Nakamura H, Noh JY, Itoh K, Fukata S, Miyauchi A, Hamada N. Comparison of methimazole and propylthiouracil in patients with hyperthyroidism caused by Graves' disease. J Clin Endocrinol Metab. Jun 2007;92(6):2157-62. Epub 2007 Mar 27. [Medline].

  3. FDA MedWatch Safety Alerts for Human Medical Products. Propylthiouracil (PTU). US Food and Drug Administration. Available at http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm164162.htm. Accessed June 3, 2009.

  4. Vanderpump M. Cardiovascular and cancer mortality after radioiodine treatment of hyperthyroidism. J Clin Endocrinol Metab. Jun 2007;92(6):2033-5. [Medline].

  5. Cawood T, Moriarty P, O'Shea D. Recent developments in thyroid eye disease. BMJ. Aug 14 2004;329(7462):385-90. [Medline].

  6. Cooper DS. Antithyroid drugs. N Engl J Med. Mar 3 2005;352(9):905-17. [Medline].

  7. deGroot LJ, Larsen RP, Hennemann G. The Thyroid and Its Diseases. 1996;371-489.

  8. Franklyn JA, Maisonneuve P, Sheppard M, et al. Cancer incidence and mortality after radioiodine treatment for hyperthyroidism: a population-based cohort study. Lancet. Jun 19 1999;353(9170):2111-5. [Medline].

  9. Mestman JH. Hyperthyroidism in pregnancy. Best Pract Res Clin Endocrinol Metab. Jun 2004;18(2):267-88. [Medline].

  10. Sarlis NJ, Gourgiotis L. Thyroid emergencies. Rev Endocr Metab Disord. May 2003;4(2):129-36. [Medline].

  11. Schwartz KM, Fatourechi V, Ahmed DD, Pond GR. Dermopathy of Graves' disease (pretibial myxedema): long-term outcome. J Clin Endocrinol Metab. Feb 2002;87(2):438-46. [Medline].

  12. Weetman AP. Graves' disease. N Engl J Med. Oct 26 2000;343(17):1236-48. [Medline].

 
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