J Korean Soc Ultrasound Med.  2011 Sep;30(3):179-185.

US Diagnosis for Thyroid Nodules with an Indeterminate Cytology

• Ha JG
• Kim DW
• Kang TW

Abstract

PURPOSE
We wanted to assess the diagnostic efficacy of thyroid ultrasound (US) for evaluating thyroid nodules with indeterminate cytology.
MATERIALS AND METHODS
Among 1865 nodules in 1278 patients who received a prospective US diagnosis of their thyroid nodule(s) and who subsequently underwent US-guided fine-needle aspiration, 130 nodules with indeterminate cytology were enrolled in the study. Each thyroid nodule was prospectively classified by a single radiologist into 1 of 5 diagnostic categories: "benign", "probably benign", "indeterminate", "suspicious for malignancy" and "malignant." The solid nodules were classified using all 5 categories and the partially cystic nodules classified using 4 categories ("indeterminate" was omitted). We calculated the diagnostic efficacy of thyroid US by comparing the US diagnoses with the pathology results.
RESULTS
Of 130 nodules with indeterminate cytology (130/1865, 7.0%), 62 nodules were surgically removed. Nineteen nodules were assigned to the indeterminate category on US. The malignantly rate of the US-indeterminate category was 56.5% (35/62). The sensitivity, specificity and positive and negative predictive values were 81.0%, 81.8%, 81.0%, 81.8% and 81.4%, respectively, when US-indeterminate nodules were excluded. There was no significant difference of diagnostic efficacy when these nodules were reclassified as malignant, but there was a significant difference of diagnostic efficacy when these nodules were reclassified as benign.
CONCLUSION
Our US classification may be a feasible method for managing thyroid nodules with indeterminate cytology.

Keyword

Thyroid nodule; Ultrasound; Fine-needle aspiration; Indeterminate; Malignancy

MeSH Terms

Biopsy, Fine-Needle
Humans
Prospective Studies
Sensitivity and Specificity
Thyroid Gland
Thyroid Nodule