Name:
Goiter: Karen Barnard, MD, MPH, discusses the clinical exam for goiters.
Description:
Goiter: Karen Barnard, MD, MPH, discusses the clinical exam for goiters.
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/a0db3304-e4b2-4607-a0ca-fb60ced744fa/thumbnails/a0db3304-e4b2-4607-a0ca-fb60ced744fa.jpg?sv=2019-02-02&sr=c&sig=qj20f1WfQ8rKNU0TO4KfVurDCwz%2Flq7diiVDJzzzkG0%3D&st=2024-10-15T23%3A52%3A17Z&se=2024-10-16T03%3A57%3A17Z&sp=r
Duration:
T00H04M51S
Embed URL:
https://stream.cadmore.media/player/a0db3304-e4b2-4607-a0ca-fb60ced744fa
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/a0db3304-e4b2-4607-a0ca-fb60ced744fa/6830492.mp3?sv=2019-02-02&sr=c&sig=%2BAnwsH3gFT166KxGkG2Kr%2Fh%2F7oZrepIdXJjW6Xceu6k%3D&st=2024-10-15T23%3A52%3A18Z&se=2024-10-16T01%3A57%3A18Z&sp=r
Upload Date:
2022-02-28T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
>> I'm Joan Stephenson, Editor of JAMA's Medical News and Perspective Section. Today, I have the pleasure of speaking with Doctor Karen Barnard on goiter, which is discussed in chapter 21 of the Rational Clinical Exam. Doctor Barnard, why don't you introduce yourself to our listeners? >> Hello, everybody. My name is Doctor Karen Barnard. I am Assistant Professor of Medicine and Endocrinology at Duke University. And I'm an Endocrinologist at the Durham VA. >> Doctor Barnard, can you please explain to our listeners what a goiter is?
>> A goiter is simply an enlargement of the thyroid gland that may result from a variety of causes. >> And what are the underlying conditions that can cause a goiter? >> The most common condition worldwide is iodine deficiency. But the other causes are things like multinodular goiter, Grave's Disease, Hashimoto's thyroiditis, subacute thyroiditis, and postpartum thyroiditis. Familial goiter and malignancy can also cause the enlarged gland. And then, lastly, goitrogens.
>> How large is the normal thyroid and what factors might affect the normal thyroid size in a given patient population? >> The normal thyroid weighs about 10 grams or less with an upper limit normal size about 20 gram. The supply of iodine in the diet affects the size of the gland. So, people who live in geographic areas where iodine deficiency is endemic tend to have larger glands, and an upper-limit normal of 35 grams is accepted in these areas. Other variables that can affect the size are the patient's body surface area and their sex.
>> In a region that is iodine-replete, what is the typical prevalence of goiter? >> In children, the prevalence is less than five percent. And in adults, the prevalence ranges from five to 10%. >> How should a clinician determine if goiter is present? >> In terms of the physical exam of the thyroid, there are no data to support the use of one technique over another. However, a few general principles apply. The first is the patient must be comfortable, either seated or standing, with the neck in a neutral position of slightly extended.
Secondly, the examiner can inspect and palpate the gland using the approach that they are most comfortable with. So, for example, whether it's standing in front of the patient and examining with thumb and forefinger, or whether it's standing behind the patient and examining with the fingers, it's all acceptable. And thirdly, while no study has actually analyzed whether a swallowing maneuver is of benefit, most examiners believe that this maneuver will accentuate the thyroid and make it easier to determine the size. And then, fourthly, to determine the size when palpating, compare the size of each lobe of the thyroid to the patient's distal thumb.
A thyroid with each lobe larger than the patient's terminal phalanx of the thumb is considered palpably enlarged. And then, the reference standard for enlargement is thyroid ultrasound. >> What factors affect the accuracy of the physical examination for a goiter? >> A false-positive diagnosis of goiter on physical exam can occur in the following types of patients. Some patients, those who have higher location of the thyroid in the neck. Patients who have Modigliani syndrome in which a long curving neck enhances the thyroid and the examiner could mistakenly believe that the gland is enlarged.
If there is a mass behind the thyroid or fat pads in the anterior lateral neck, that can also lead the examiner to think the thyroid is larger than it actually is. And then, factors that may result in missing the diagnosis in a patient in whom the exam is more technically difficult. So, for instance, obese patients or those patients who have COPD or a short neck. And then, those in whom the thyroid is located in an unusual location such as retrosternal might make the examiner miss the gland.
>> Is there anything else that you would like to tell our listeners about examining patients for goiter? >> Yes. While there are not recommendations to routinely screen for thyroid disease with a physical exam or a TSH, there are certain populations who are at higher risk of getting a goiter. And in these patients, a screening should be considered. And I'd like to review them with the listeners. The first is if a patient presents with symptoms of hypo or hyperthyroidism, children, especially those who live in endemic iodine-deficient areas.
Pregnant, and lactating women, elderly patients, patients who've had excessive radiation exposure, and patients with Down Syndrome should be considered for screening. >> Thank you, Doctor Barnard, for this summary of goiters. For additional information about this topic, JAMAevidence subscribers can consult chapter 21 of the Rational Clinical Exam. This has been Joan Stephenson of JAMA, talking with Doctor Karen Barnard for JAMAevidence.
