Feasibility of an Ultrasonographic Categorical Reporting System for Thyroid Incidentaloma

ABSTRACT

PURPOSE: To evaluate the feasibility of an ultrasonographic category system for the proper management of incidentally found thyroid nodules. MATERIALS and METHODS: We retrospectively evaluated 2,688 patients who had thyroid nodules and underwent ultrasonography-guided fine needle aspiration biopsy. We made an ultrasonographic categorical reporting system by logistic regression analysis for comparison with the pathologic results of cytology and biopsy. RESULTS: The distribution of malignancy probability for benign nodules was 0.07 to 0.23 and for malignant nodules was 0.37 to 0.91 (95% confidence intervals). We stratified the distribution of the probability of malignancy of each nodule into 6 categories (category 0, no nodule; 1, highly suggestive of benignancy; 2, probably benign; 3, indeterminate; 4, probably malignant; and 5, highly suggestive of malignancy) and summarized the representative US findings. We compared the category of each nodule with the pathological results. In nodules with surgically proven pathologic diagnoses, benign lesions were 96.1% (348/361) in category 1 and malignant lesions were 98.6% (139/141) in category 5. CONCLUSION: We suggest that the ultrasonographic category system for thyroid incidentaloma may provide optimal strategies to manage incidentally found thyroid nodules.