Elastosonography scoring and strain index of thyroid nodules with Hurthle cells

This study evaluated the effectiveness of elastosonography (ES) scoring and strain index (SI) in diagnosing patients with thyroid nodules composed primarily of Hurthle cells.

This study retrospectively analyzed 57 patients with thyroid nodules composed predominantly of Hurthle cells on fine needle aspiration cytology (FNAC). Patients were evaluated by thyroid ultrasonography (US), ES scoring, SI, US guided FNAC, and histopathology.

Histopathologically, 12 (21.1%) nodules were malignant and 45 (78.9%) were benign. Mean age, sex distribution, thyroid function tests, and morphologic features on US were similar in the malignant and benign groups. Mean SI (40.98±31.28 vs 21.24±25.47, p=0.027) and thyroid peroxidase antibody (anti-TPOab) positivity (p=0.004) were significantly higher in malignant than in benign nodules. Receiver operating curve (ROC) analysis showed that an SI cutoff of 10.326 had a sensitivity of 91.7% and a specificity of 49%, and an SI cut-off of 64.807 had a specificity of 91.1% and a sensitivity of 25%. The optimal SI cut-off value, 17.877, had a sensitivity of 66.7%, a specificity of 66.7%, a positive predictive value (PPV) of 34.8%, a negative predictive value (NPV) of 88.2%, and an area under the ROC curve of 73.1±0.074% (95% CI: 58.7-87.6.5%). The sensitivity, specificity, PPV, NPV and diagnostic accuracy of ES scoring were 41.6%, 91.1%, 55.5%, 85.4% and 80.7%, respectively.

This is the first study to investigate ES scoring and SI in nodules composed predominantly of Hurthle cells on FNAC. ES scoring and SI may add some contribution to ultrasonography in the characterization of thyroid nodules with Hurthle cells.