Should we use ultrasound features associated with papillary thyroid cancer in diagnosing medullary thyroid cancer?

In thyroid nodule management, ultrasound (US) features, such as hypoechogenicity of the lesion, irregular margins, microcalcifications, and intralesional vascular signal, alone or combined, have to be considered as suggestive for malignancy. Because of the low prevalence of medullary thyroid cancer (MTC), a few papers analyzed US characteristics associated with this cancer in small series, with controversial results. Aim of this study was to evaluate in MTC the US risk factors of thyroid nodule. In this order, a series of nodules histologically proven as MTC and a group of nodules with histology of papillary cancer (PTC) were retrospectively compared with a control group of benign nodule. Fifty percent MTC were solid hypoechoic and 16% showed microcalcifications with significant difference with respect to the benign group (p