McGill Thyroid Nodule Score in Differentiating Benign and Malignant Pediatric Thyroid Nodules: A Pilot Study

Abstract

Objective The McGill Thyroid Nodule Score (MTNS) is a preoperative tool used to predict the risk for well-differentiated thyroid cancer given a specific nodule in adults. We evaluated the clinical utility of a modified pediatric MTNS with children and adolescents. Study Design Case series with chart review. Setting Tertiary care children’s hospital. Subjects and Methods This is a retrospective chart review of 46 patients ≤18 years of age presenting with a solitary or dominant thyroid nodule treated with surgical resection between September 2008 and December 2015. The cumulative MTNS for each nodule was calculated and compared with the final pathology. Results Of 46 patients, 10 (21.7%) were diagnosed with well-differentiated thyroid cancer (80% papillary thyroid carcinoma, 10% follicular variant of papillary thyroid carcinoma, 10% follicular thyroid carcinoma). Malignant nodules were associated with a greater mean MTNS (benign, 5.72 ± 3.03; malignant, 16 ± 3.13; P < .05). The sensitivity, specificity, and positive predictive value of malignancy were 100%, 94.4%, and 83.3% for scores ≥10 and 80%, 100%, and 100% for scores ≥11, respectively. In nodules with indeterminate cytology (Bethesda III and IV), the pediatric MTNS showed good differentiation between benign and malignant disease, with mean scores of 7.95 and 12.5, respectively ( P = .006). Conclusion This pilot study suggests that a comprehensive scoring system may help assess the risk of malignancy in pediatric thyroid nodules and differentiate nodules with indeterminate cytology into higher- and lower-risk categories. Given these findings, larger, multi-institutional studies are warranted.