Relative risk of cancer in sonographically detected thyroid nodules with calcifications

Purpose, The aim of this prospective study was to evaluate the significance of sonographically detected thyroid calcifications in the diagnosis of thy roid cancer. Methods. One hundred eighty-eight patients with thyroid disease, including 37 with thyroid cancer, were included in the study. Each patient underwent preoperative, high-resolution sonography to evaluate the thyroid gland for the presence of calcifications. Results. The highest incidence of calcification was found in thyroid cancer (54%), followed by multinodular goiter (40%), solitary nodular goiter (14% ), and follicular adenomas (12%). The incidence of cancer was significantly higher in calcified nodules (29%) than in noncalcified nodules in the enti re group (14%) (p = 0.019), with a relative risk of 2.5. In the group of so litary thyroid nodules, the incidence of cancer in the calcified nodules (5 5%) was higher than in the nodules without calcification (23%) (p = 0.016). Multiple non calcified thyroid nodules harbored cancer in only 5% of cases . Compared with multiple noncalcified thyroid nodules, the solitary calcifi ed nodules demonstrated a relative risk of 22.8. In both the solitary and m ultiple nodules, the relative risk in the presence of calcification was abo ut the same, around 4. Patients younger than 40 years with calcified nodule s constituted a high-risk group, with a relative risk of 3.8 versus 2.5 in patients older than 40 years with calcified nodules. Conclusions. The detection of thyroid calcifications by sonography is diagn ostically valuable, especially in cases involving a solitary nodule or a yo ung person. The presence of calcifications in these cases should raise the suspicion of malignancy. The low incidence of cancer in patients with multi ple noncalcified thyroid nodules suggests that a more conservative approach may be appropriate in such cases. (C) 2000 John Wiley & Sons, Inc.