MON-396 Macrocalcification Patterns In Thyroid Nodules: Association With Malignancy And Assessment Of Ata And Tirads Scoring

Abstract Disclosure: M. Garver: None. C. Deutsch: None. B. Sheridan: None. H. Zhao: None. C. Vaz: None. Current ATA guidelines state that macrocalcifications carry a malignancy risk only if combined with microcalcifications.1 Interrupted peripheral macrocalcifications, in association with a soft tissue rim outside the calcification, are highly likely to be malignant but do not carry a malignancy risk independently.1 We previously reported that macrocalcifications were seen in 70% of malignant thyroid nodules and were significantly associated with risk of malignancy. 2 For this analysis, we sought to identify sonographic patterns of the macrocalcifications in thyroid nodules and their risk of malignancy. We also sought to perform an exploratory analysis of the ATA and TIRADS scoring system for nodules with macrocalcifications. 76 nodules with macrocalcifications were identified; 17 were excluded due to missing images, yielding 59 nodules (n=10 benign, n=49 malignant). US images were independently reviewed by trained endocrinologists. Nodules were scored according to ATA and TIRADS criteria and pattern of macrocalcification was identified. Demographic data, thyroid function tests were analyzed. There was no statistically significant correlation between age, sex, smoking status, BMI or thyroid function tests with presence of macrocalcifications. Of 59 nodules, 24 had peripheral rim and 35 had intranodular coarse macrocalcifications. Malignancy was present in 75% of nodules with peripheral rim macrocalcifications (n=18) and 89% of those with intranodular coarse macrocalcifications (n=31). There was no statistical significance in rate of malignancy between the 2 patterns analyzed (Pearson chi =1.8629, p = 0.172). In regard to TIRADS and ATA analysis, since this was an exploratory study, the focus of this initial analysis was on detecting positives. ATA scoring demonstrated a sensitivity of 87.8% (95% CI: 79.4–96.1%) and PPV 81.1% (95% CI: 71.2–91.1%) for malignancy with nodules with macrocalcifications. TIRADS scoring showed a sensitivity of 71.4% (95% CI: 59.9–83.0%) and PPV of 77.8% (95% CI: 67.2–88.4%) for malignancy. Specificity and negative predictive value were not calculated due to the small number of true negatives in this sample. Intranodular macrocalcifications showed a higher malignancy rate than peripheral rim, but the difference was not statistically significant. Limitations of this study include the small sample size and unbalanced cohort of malignancy vs benign. Further validation on a larger, more balanced dataset is required. References 1. Haugen BR et al. Thyroid. 2016;26(1):1–1332. Reznick T et al. J Endocr Soc. 2019;3(Suppl 1):MON-574 Presentation: Monday, July 14, 2025