Background: Elastography is a newly developed dynamic technique that employs ultrasound (US) to provide an estimation of tissue stiffness by measuring the degree of distortion under the application of an external force. US elastography has been applied to differentiate malignant from benign lesions.

Patients: This study included 92 consecutive patients with a single thyroid nodule who underwent surgery for compressive symptoms or suspicion of malignancy on fine needle aspiration (FNA) cytology. Tissue stiffness on US elastography was scored from 1 (greatest elastic strain) to 5 (no strain).

Results: On US elastography score 1 and 2 were found in 49 cases, all benign lesions; score 3 in 13 cases, 1 carcinoma and 12 benign lesions; score 4 and 5 in 30 cases, all carcinomas. Thus, the elasticity scores 4-5 were highly predictive of malignancy (p<0,0001) with a sensitivity of 97%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 98%. In 32 patients with an indeterminate FNA result the conventional US was not predictive of malignancy, while an US elastographic score 4-5 was observed in 6/7 (86%) patients with carcinoma on histology, and score 1-3 in all the 25 patients with benign lesions.

Conclusion: US elastography has great potential as an adjunctive tool for the diagnosis of thyroid cancer, especially in indeterminate nodules on cytology. Larger prospective studies are needed to confirm these results and to establish the diagnostic accuracy of this new technique