Unsuspected Thyroid Nodules
Unsuspected thyroid nodules are fairly common and ultrasound is the best method to visualize
Many patients are surprised to find they have thyroid nodules during routine physical examination or during an unrelated imaging procedure. These nodules are called unsuspected thyroid nodules and are becoming more common. In both autopsy studies and in studies on patients with one ore more nodules that were felt on physical exam, multiple other nodules are found frequently. These nodules are best visualized with ultrasound.
In an autopsy survey 821 patients with evaluated and they all had normal thyroids on physical examination and no known history of thyroid disease. 49.5% had nodules at autopsy. Of these, 12.2% had a single nodule and 37.3% had multinodular goiter. 4.8% of all these nodules were thyroid cancers. (1)
In another study on patients seen in a community clinic, there were 151 patients who were found to have a single nodule on physical exam by an endocrinologist. Ultrasound was completed on all these patients and 48% of these patients had more than one nodule on ultrsound exam. 33% had more than three nodules. (2)
Thus, even in experienced hands, physical examination is not 100% accurate in the diagnosis of thyroid nodules and many times there are multiple nodules seen with ultrasound. Fortunately the rate of thyroid cancer is low.
(1) Mortenson JD: JCEM 1955
(2) Tan B and Gharib H: Arch Internal Medicine, 1995