Five-year follow-up shows the overwhelming majority remain harmless
WebMD News from HealthDay
By Amy Norton
HealthDay Reporter
TUESDAY, March 3, 2015 (HealthDay News) -- Harmless growths in the thyroid gland are common, and a new study suggests they don't need to be monitored as closely as current guidelines recommend.
The thyroid is a gland in the neck that secretes hormones involved in metabolism. According to the American Thyroid Association, by age 60 about half of all people develop a thyroid nodule, an abnormal lump of cells within the gland.
Most nodules cause no symptoms, the association says, and they are only detected by chance, when someone has an imaging test for an unrelated reason -- such as a CT scan of the chest or an ultrasound of the carotid arteries in the neck.
If the nodule is large enough, doctors will do a biopsy -- using a fine needle to extract some cells -- to see whether the lump is cancerous. More than 90 percent of the nodules are deemed benign, or harmless, the association says.
"But the question still is, what if that [biopsy result] is a false-negative?" said Dr. Anne Cappola, an endocrinologist at the University of Pennsylvania.
Because of that, thyroid association guidelines say that people with benign nodules should get follow-up ultrasound scans after one year, and then "periodically" after that, said Dr. Hossein Gharib, a past thyroid association president and a professor of medicine at the Mayo Clinic in Rochester, Minn.
If the nodule grows by about 50 percent in volume, guidelines say a repeat biopsy should be done, Gharib said.
But the new study, published March 3 in the Journal of the American Medical Association, challenges the need for such close monitoring in many cases.
Italian researchers followed nearly 1,000 patients with presumably benign thyroid nodules. All patients had either had a biopsy, or had skipped the biopsy because an ultrasound showed their nodules to be tiny and free of suspicious features that could signal cancer.
Over five years of monitoring with yearly ultrasound scans, most patients' thyroid nodules showed no substantial change. For 15 percent, the nodule grew by 50 percent in volume, while it shrank for 19 percent.
source : Study Questions Close Monitoring of Thyroid Growths
