Best Practice & Research Clinical Endocrinology & Metabolism
1Epidemiology of thyroid nodules
Section snippets
Palpation
With palpation, the least sensitive method for detecting thyroid nodules, prevalence has been estimated to be about 4%.12 A sample of 4469 people from Framingham, Massachusetts, who were randomly selected from the city's total population of 10,000 (in 1948) and 740 volunteers were studied with physical examination and several laboratory tests every 2 years and observation for up to 15 years. Of the 5127 participants who were alive at last follow-up, 4% had non-toxic thyroid nodules, none of
Ultrasonography
In one study that used high-resolution ultrasound (HRUS), the prevalence of thyroid nodules was reported to be as high as 67%.18 This prospective cohort study assessed the prevalence of thyroid nodules in the community and compared findings obtained by using palpation with those obtained by using HRUS in 100 asymptomatic North American subjects without known thyroid disease. Of the participants, 21% had palpable nodules (solitary nodules, 9%; multiple nodules, 12%). With HRUS measurement, 22%
Data from autopsy studies
Autopsy data provide the gold standard for determining the true prevalence of thyroid nodules. Several autopsy studies have been performed in non-endemic and endemic goiter areas.23, 24, *25, 26, 27, 28 The prevalence of thyroid nodules in these studies was 82–650 per 1000 autopsies (Table 3).13
In addition, autopsy data from patients with no history of thyroid disease have indicated a 50% prevalence of thyroid nodules.25 Thyroid glands from 1000 consecutive subjects without previous evidence of
Dilemmas of incidentalomas
The increased sensitivity of ultrasonography has led to the detection of thyroid nodules that are too small to palpate and have indeterminate clinical significance. According to Black and Welch: ‘advances in diagnostic imaging create confusion in two crucial areas of medical decision making: establishing how much disease there is and defining how well treatment works’.29 The challenge facing the clinician is to avoid unnecessary diagnostic intervention or treatment, or both, that confers little
Summary
Thyroid nodules are common in clinical practice. Their prevalence depends largely on the screening method and the population evaluated. Increasing age, female sex, iodine deficiency, and a history of head and neck radiation seem consistently to increase the risk of thyroid nodules.*1, 2, 3 With palpation, the least sensitive method for nodule detection, prevalence has been estimated to be around 4%.12 Autopsy data from patients with no history of thyroid disease have indicated a prevalence of
Conflict of interest statement
Dr Gharib is the recipient of a research grant from Genzyme Corporation.
References (39)
Changing concepts in the diagnosis and management of thyroid nodules
Endocrinology and Metabolism Clinics of North America
(1997)- et al.
Total thyroidectomy is the preferred treatment for patients with Graves' disease and a thyroid nodule
Otolaryngology and Head and Neck Surgery
(2007) - et al.
The epidemiology of thyroid disease and implications for screening
Endocrinology and Metabolism Clinics of North America
(1997) - et al.
Thyroid incidentalomas: prevalence, diagnosis, significance, and management
Endocrinology and Metabolism Clinics of North America
(2000) - et al.
Fine-needle aspiration cytology of the thyroid: a 12-year experience with 11,000 biopsies
Clinics in Laboratory Medicine
(1993) - et al.
Aberrant thyroid glands
The American Journal of Pathology
(1928) - et al.
Nodular thyroid disease: evaluation and management
The New England Journal of Medicine
(1985) - et al.
The spectrum of thyroid disease in a community: the Whickham survey
Clinical Endocrinology
(1977) - et al.
Association between serum insulin-like growth factor-I levels and thyroid disorders in a population-based study
The Journal of Clinical Endocrinology and Metabolism
(2007) - et al.
The spectrum of thyroid disorders in adult type 1 diabetes mellitus
Diabetes/Metabolism Research and Reviews
(2007)