Abstract
Background: There is no clear consensus on risk of malignancy from macrocalcifications identified on thyroid ultrasound (US) (1-4). We conducted a retrospective analysis evaluating the association between the presence and pattern of macrocalcifications on thyroid ultrasound and risk of thyroid cancer. Methods: Using EPIC electronic medical record (EMR) a retrospective review of patients who underwent thyroidectomy at three different institutions between January 1, 2010 - March 31, 2017 was performed. Surgical pathology, cytology by fine needle aspiration (Bethesda classification), and demographic variables including age, ethnicity, sex, body mass index, smoking history, thyroid function tests, and thyroid antibodies were analyzed. Thyroid US images were independently reviewed to classify pattern of macrocalcification. Results: 490 patients who underwent total thyroidectomy were identified. 350 (72%) were female, 296 (61%) were Caucasian, 273 (56%) were never smokers. The mean BMI was 30.2. 138 (28%) were reported to have any pattern of calcification on thyroid ultrasound performed prior to surgery. Of those calcifications, 76 (55%) were macrocalcifications and 62 (45%) were microcalcifications. 69.7% of nodules with macrocalcifications and 66.1% with microcalcifications were found to be malignant. 82.3% of benign nodules did not show any calcification. (Pearson chi2 = 28.1112, DF 2, p <0.001). There was no statistically significant correlation between age, sex, smoking status, BMI, thyroid function tests, or thyroid antibodies with presence of macrocalcifications. Conclusions: The sonographic presence of microcalcifications is known to be associated with the presence of papillary thyroid cancer. This has been incorporated into the ATA guidelines for evaluation of thyroid nodules. However, the risk of malignancy associated with macrocalcifications on thyroid ultrasound is not clear. In our sample of 490 cases, we found that macrocalcifications were seen in 70% of malignant nodules and were significantly associated with risk of malignancy. Continued research on evaluating various patterns of macrocalcifcation and their individual risk of malignancy in thyroid nodules is being planned. References: 1. Kim BK et al. (2013) Relationship between patterns of calcification in thyroid nodules and histopathologic findings. European Journal 60:155-160 2. Taki S et al. (2004) Thyroid calcifications: sonographic patterns and incidence of cancer. Clin Imaging 28:368-371. 3. Seiberling KA et al. (2004) Role of intrathyroidal calcifications detected on ultrasound as a marker of malignancy. Laryngoscope 114:1753-1757. 4. Lee J, Lee SY et al. (2012) Thyroid 23:1106-1112