In thyroid nodule management, ultrasound (US) features, such as hypoechogenicity of the lesion, irregular\ud margins, microcalcifications, and intralesional vascular signal, alone or combined, have to be considered as suggestive for\ud malignancy. Because of the low prevalence of medullary thyroid cancer (MTC), a few papers analyzed US characteristics\ud associated with this cancer in small series, with controversial results. Aim of this study was to evaluate in MTC the US risk\ud factors of thyroid nodule. In this order, a series of nodules histologically proven as MTC and a group of nodules with\ud histology of papillary cancer (PTC) were retrospectively compared with a control group of benign nodule. Fifty percent\ud MTC were solid hypoechoic and 16% showed microcalcifications with significant difference with respect to the benign\ud group (p<0.05 for both parameters), while no significant difference was recorded regarding margins nor nodular\ud vascularization. The presence of at least one US risk feature was almost equal in MTC (58.3%) and controls (55.5%). On\ud the contrary, at least one US risk factor was significantly (p<0.001) more frequent in PTC than in benign group or MTC\ud series. This study showed low frequency of ultrasound features associated to PTC when analyzed in medullary cancer.\ud Because of the poor literature focusing on this topic, and the herein used design, these data contribute to the knowledge\ud about presentation of MTC at US. We advice for further prospective studies on larger series to define the US presentation\ud of this cancer type

A very low rate of lesions with indeterminate cytology are BRAF mutated. Thus, the role of this biomarker to detect or exclude cancers in patients with such FNA reports is marginal and should be reconsidered in guidelines.

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Thyroglobulin (Tg) is a key marker in the follow-up of differentiated thyroid cancer (DTC). Diagnostic accuracy of serum Tg is higher after TSH stimulation than during thyroxine treatment. However, some studies suggest that TSH stimulation could be not necessary in a large part of patients, if Tg is measured by high sensitive assay under replacement therapy. The aim of this study was to evaluate the need of Tg stimulation test in DTC followed-up by sensitive Tg assay. In a prospective multicenter explorative study, 68 low or high risk patients underwent Tg measurement on thyroxine (ON-LT4-Tg) and after LT4 withdrawal (OFF-LT4-Tg). Undetectable ON-LT4-Tg and OFF-LT4-Tg values (i. e.,<0.15 ng/ml) were found in 56/68 patients, all with negative imaging workup. Twelve subjects had skewed OFF-LT4-Tg: 8 cases had increased ON-LT4-Tg and local recurrence (n=6), distant metastasis (n=1), or benign thyroglossal duct (n=1); the remaining 4 patients had undetectable ON-T4-Tg but detectable OFF-LT4-Tg and neck metastasis was recorded in one of these. By ROC analysis, the most accurate cutoff for ON-LT4-Tg and OFF-LT4-Tg were set at 0.23 ng/ml and 0.70 ng/ml, respectively. A positive ON-LT4-Tg value accurately predicts a positive stimulation test and confers an Odds Ratio of 464 (95% CI from 26.3 to 8 173.2, p<0.0001) to have persistent/recurrent disease. This study shows that DTC patients with ON-LT4-Tg below 0.23 ng/ml by our high sensitive assay should be considered disease free and they can avoid Tg stimulation test. High sensitive Tg assays should be used to better manage DTC patients.

The relation between thyroid ultrasonography and laboratory, and the relationship of thyroid volume with clinical and anthropometric parameters, are not well clarified. Aim of the study was to investigate normal and hypoechoic-inhomogeneous not nodular thyroid gland in predicting thyroid tests, and to assess the correlation of thyroid volume with several clinical parameters. The series included 434 subjects (244 with normal thyroid ultrasonography, and 190 with hypoechoic-inhomogeneous thyroid) at their first evaluation. Subjects with normal ultrasonography and skewed tests were re-evaluated after one year. All subjects with normal ultrasound showed normal free-T-4, while TSH was elevated in 9.8% of cases and thyroid antibodies were positive in another 9.8%. In patients with hypoechoic-inhomogeneous thyroid, free-T-4 was low in 33.2%, TSH was elevated in 78.4% and thyroid antibodies were positive in 76.3%. Normal ultrasonography matched with normal tests in 81.1% of cases while hypoechoic-inhomogeneous thyroid in 9.5% (p<0.001). The re-evaluation of tests showed no significant difference. In subjects with both normal ultrasonography and tests, thyroid volume was correlated with age (p=0.001), weight (p=0.003), BMI (p=0.04), body surface area (p=0.002). Thyroid laboratory assessment was different between subjects with ultrasonographically normal or hypoechoic-inhomogeneous thyroid. Thyroid volume of thyroid diseases-free subjects was correlated with age, weight, BM I and body surface area, and this should be of interest to investigate the references of normality of thyroid size