The prevalence of benign thyroid nodules is high and there are certain
ultrasound features, suggesting malignancy, that can help radiologists
determine whether or not a biopsy is needed, according to a study
performed at the University of California San Francisco Medical Center,
San Francisco, CA.
A total of 245 patients (54 patients with
cancer, 191 patients with no cancer) were analyzed. “Our study supports
previous data showing that some sonographic features of thyroid nodules
are suggestive of malignant nature and should lead to biopsy,” said
Dorra Sellami, MD, lead author of the study. “These features include
microcalcifications (which increase the risk of cancer 16 folds), a
shape taller than wide (increases the risk of cancer 3.7 folds) and
hypoechogenicity (two-fold increase in risk of cancer). Other features
may suggest that a nodule is benign, such as hyperechogenicity (40%
increase in risk of cancer),” she said. “Current clinical guidelines
recommend biopsy of all lesions greater than or equal to 10 mm.
However, in our study of patients with no thyroid cancer, 49% had at
least one nodule greater than or equal to 10 mm,” said Dr. Sellami.
“Very few thyroid nodules are obviously malignant or benign. Most
thyroid nodules we see by ultrasound are indeterminate, and in order to
rule out cancer, a fine needle aspiration is often recommended. This
results in a ratio of ten benign nodules sampled for one cancer
diagnosed,” she said.
“Our findings will help radiologists and clinicians determine which
nodules are definitely not suspicious and can be watched. I think that
our study is one step toward decreasing the number of invasive
procedures in patients with benign thyroid nodules—while maintaining
the same vigilance in detecting thyroid cancer in its early stages,”
said Dr. Sellami.
-- News release courtesy of The American
Roentgen Ray Society (ARRS)