The predictive value of elastography in thyroid nodules and its comparison with fine-needle aspiration biopsy results

We aimed to evaluate the predictive value of elastography in determining malignancy during preoperative investigation of thyroid nodules and to compare its results with preoperative fine-needle aspiration biopsy (FNA) and postoperative histopathology results.

Among the group of patients who had indications for thyroidectomy between January 2013- September 2013 in the department of general surgery 86 euthyroid patients were prospectively included in the study. Informed consent was obtained from all patients. All patients received simultaneous thyroid ultrasonography and elastography by an experienced radiologist. The patients were classified into five scores according to Tsukuba scoring. Score 1 and 2 were evaluated as soft nodules (benign), score 3 as medium consistency (usually benign), and scores 4 and 5 as hard nodules (malignant). For statistical purposes, the FNA results were classified as benign, probably benign or malignant. The histopathological results were classified as benign or malignant. The results were compared with FNA and elastography findings.

The fine-needle aspiration biopsy of the nodules revealed 60.5% benign, 17.4% high probability of benign, and 22.1% malignant cases; and the elastography diagnosed 38.4% benign, 23.3% high probability of benign, and 38.4% malignant nodules. The postoperative pathology evaluation diagnosed 67.4% of patients as benign, and 32.6% as malignant. The rate of detection of thyroid cancer cases (sensitivity) by elastography was 67.9%, the ability to distinguish healthy individuals (specificity) was 75.9%, and the overall adequacy of the method (accuracy) was determined as 73.3%.

Elastography overlaps with especially benign cytology-pathology at a high rate, and provides definite diagnosis in 58% of malignant cases. In our study, elastography provided more reliable results than FNA, in terms of diagnosing malignancy.