Search

Background: Ultrasonography (US) changes have been noted in patients with autoimmune thyroiditis (AT). Here, we report that some patients with late stage AT have a distinctive, previously unreported finding on US that we call the "hypoechoic triangle sign" (HET)., Methods: On US, the HET sign was characterized as a well-defined area of low echogenicity, about 10 mm in diameter, between the lateral margin of one or both thyroid lobes, the medial wall of the carotid artery, and, posteriorly, the prevertebral muscles. Twenty-six patients with AT who had the HET sign (Group 1) were compared with 71 patients with AT who had normal serum thyrotropin (TSH) and free thyroid hormones levels (Group 2) and with 154 normal controls (Group 3). TSH was tested at least twice, first as part of their regular clinical care and then in follow-up. The groups were similar in terms of age, sex, and body mass index. Thyroid volume by US, TSH, free triiodothyronine, free thyroxine, antithyroid antibodies, and l-thyroxine treatment were evaluated. Sonographic gray-scale analysis and three-dimensional reconstruction of HET region were performed in five of the Group 1 patients., Results: Thyroid volume was significantly smaller (p < 0.01) in Group 1 than in Groups 2 and 3 (6.9 ± 2.18 vs. 10.4 ± 2.1 and 9.8 ± 2.5 mL, respectively). In Group 1, 61.5% of subjects were taking l-thyroxine for hypothyroidism; none of the Group 2 or 3 patients was taking thyroid hormone. Serum TSH was significantly higher (p < 0.01) in Group 1 versus Groups 2 and 3 (3.6 ± 1.3 vs. 2.18 ± 1.4 and 1.9 ± 1.1 mIU/L, respectively). None of the Group 2 or 3 patients had the HET sign. Gray-scale US demonstrated an overlap between HET zone and the surrounding muscle tissue., Conclusions: The HET sign seems to be specific for overt thyroid failure in patients with AT as it was not noted in patients with AT not having overt thyroid failure. The incidental finding of the HET sign during cervical US examination should prompt obtaining thyroid function tests to rule out hypothyroidism. Our study provides data regarding specificity but not sensitivity of the HET sign for AT and thyroid failure because a consecutive group of AT patients with thyroid failure was not studied. In addition, the specificity of the HET sign for AT needs to be evaluated further by studying a diverse group of thyroid diseases.

Small hyperechogenic nodules occurring in thyroiditis frequently raise the question of their nature requiring additional evaluation. Given the scarcity of the studies addressing this issue, we have investigated whether cytopathological analysis of fine needle aspirates (FNA) of these lesions may be of diagnostic relevance. In this preliminary study, we submitted to cytopathological analysis 10 nodular lesions as well as the normal counter-lateral tissue. In none but one of the cases analyzed, the cytopathology was able to detect differences between the hyperechogenic models and the hypoechogenic parenchyma suggesting that these lesions bear no-clinical relevance. Therefore, FNA of these nodules is not advisable and should be limited to those with defined at risk clinical features.

The authors present their statistical results in terms of maximum velocity and resistive Index of the inferior thyroid artery in a group of 200 patients, all with different diseases of the gland, but without hyperthyroidism. Measurements were taken in the first tract of the inferior thyroid artery, deep and posterior to the common carotid, without encountering any significant difficulties in 83% of cases, the determinations taking less than one minute; in some patients stretching or rotation of the neck was necessary in order to obtain a good result. The maximum systolic velocities were in agreement with those reported in the literature, but statistical analysis showed a significant correlation between systolic peak and certain groups or types of disease and, albeit less reliably, between the Resistive Index and type of disease. The section of the individual vessels showed no statistically significant variations. The results indicate a possible correlation between peak systolic velocity and Reistive Index in patients without hyperthyroidism, and therefore it may now be useful to study the relationship between these two parameters also in patients with normal serum levels of thyroid hormones.

The authors report on a series of 1,043 fine-needle biopsies of the thyroid performed under US guidance; the patients had been selected for thyroid pathologic conditions. Fifty-two neoplasms were observed (46 papillary carcinomas, 1 medullary carcinoma, 2 follicular carcinomas, and 3 metastases), which had been detected by cytology and confirmed by histology or autopsy. The authors focus on 46 cases of papillary carcinoma: their US features were studied which, through a correlation of variables, allow a quick and "safe" recognition of the type of carcinoma (papillary carcinomas account for nearly 60% of thyroid neoplasms). Tumor echogenicity and outline, and the presence/absence of calcifications were evaluated: in most cases, papillary carcinomas presented as focal lesions (alone or associated with other goiter lesions), with irregular and blurred outline, no hypo/anechoic halo and, in about 1/3 of the cases, with calcifications and colliquative areas. In 17% of papillary neoplasms, metastases to loco-regional nodes were observable at US; in 3 cases the carcinoma did involve a loco-regional node but there were no US signs suggestive of it. The incidence of neoplasms on the total of fine-needle biopsies is 4.9%, while in a previous series of 3,038 fine-needle biopsies, without US guidance, on clinically detectable lesions, the figure was about 2%.