Is elastography actually useful in the presurgical selection of thyroid nodules with indeterminate cytology?

Although fine-needle aspiration cytology remains the mainstay of the preoperative workup of thyroid nodules, those with follicular proliferation still represent a diagnostic challenge. Real-time elastography (RTE) estimates the stiffness/elasticity of lesions and is regarded as a promising technique for the presurgical selection of thyroid nodules (including those with indeterminate cytology).

Our aim was to verify the potential role of RTE in the presurgical diagnosis of cancer in a large cohort of consecutive patients with follicular thyroid nodules.

One hundred two patients were submitted to conventional ultrasonography and RTE evaluation before being operated on for thyroid nodule with indeterminate cytology (54% single nodules). Tissue stiffness on RTE was scored from 1 (greatest elasticity) to 4 (no elasticity).

At conventional ultrasonography examination, the nodules (median diameter 2.2 cm) were solid (cystic areas < 10%); microcalcifications were detected in 56% of them and a hypoechoic pattern in 64%. Elasticity was high in eight cases only (score 1-2) although low in 94 (score 3-4). Cancer was diagnosed in 36 nodules (35%), being associated with microcalcifications (P < 0.0001) and inversely related to nodule diameter (P < 0.01). Malignancy was detected in 50% of the nodules with RTE score 1-2 and in 34% of those with score 3-4. Therefore, either the positive (34%) or the negative predictive value (50%) was clinically negligible.

The current study does not confirm the recently reported usefulness of RTE in presurgical selection of nodules with indeterminate cytology and suggest the need for quantitative analytical assessment of nodule stiffness to improve RTE efficacy.