Results of retrospective classification of thyroid FNAs according to the Bethesda system: would this have improved accuracy?

OBJECTIVES: To retrospectively reclassify the results of fine needle aspiration (FNA) cytology at our institution according to the Bethesda system for reporting thyroid cytopathology (TBSRTC), and to determine whether the introduction of the new classification system would have influenced the diagnostic accuracy compared with our existing system in which suspicious/indeterminate categories (categories III-IV) are managed according to clinical findings and cytopathologists' recommendations. METHODS: FNAs performed under ultrasound guidance between 2001 and 2012, and subsequently verified by histology or repeat FNA and follow-up, were reviewed and retrospectively reclassified according to TBSRTC. RESULTS: Among a total of 1310 histologically verified FNAs, the positive predictive values (%) for malignancy and neoplasia (carcinoma + follicular adenomas) for category I-VI according to the TBSRTC were 5.7/11.3, 2.6/5.5, 14.4/34.2, 23.6/55.0, 57.0/64.5 and 92.2/94.2, respectively. Although all the categories predict malignancy closely, the difference in malignancy rate between categories III and IV was not statistically significant; however, the difference in total neoplasia rate reached statistical significance. When patients with cytological and clinical follow-up were included, the malignancy rated dropped in category I to 2.4%, whereas, in category III, it remained at 13%. Repeat FNA instead of direct surgery spared half of the patients from surgery. The cytopathologists' recommendations for histological verification in category III were associated with an insignificant increase in malignancy rate, but the total neoplasia rate reached 57.5%. CONCLUSIONS: At our institution, the application of the TBSRTC did not improve the diagnostic accuracy for the detection of malignancy compared with current practice. In selected cases with cytological results falling into category III (according to clinical data and cytopathologists' opinions), direct lobectomy seems to be justified.

The gold standard of thyroid nodule examination? Prospective validation of the ACR TI-RADS in a secondary referral center.

The aim of this prospective study was the validation of the risk stratification of thyroid nodules using ultrasonography with the American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS) and partly in comparison to American Thyroid Association (ATA) guidelines in a secondary referral center. Fine needle aspiration biopsy (FNA) (n=605) and histological examinations (n=63) were the reference standards for the statistical analysis. ACR TI-RADS cut-off value: TR4 with sensitivity 85.7 %, specificity 54.1 %, PPV 58.5 %, accuracy 67.7 % (AUC 0.738; p<0.001). ATA cut-off value: "high suspicion" with sensitivity 80 %, specificity 83.3 %, PPV 80 %, accuracy 81.8 % (AUC 0.800; p=0.0025). 18.4 % nodules (3 malignant) could not be assigned to a proper ATA US pattern group (p<0.0001). Both ACR TI-RADS and ATA have allowed fair selection of nodules requiring FNA with superiority of ACR TI-RADS according to classification of all thyroid nodules to the proper group. According to ACR TI-RADS almost one third of the patients were incorrectly classified with 17.9 % missed thyroid carcinomas, exclusively micropapillary carcinomas, even though, the amount of FNA would be reduced to 48 %.

Mannan-based conjugates as a multimodal imaging platform for lymph nodes.

We show that mannan-based conjugates possess exceptional features for multimodal imaging because of their biocompatibility, biodegradability and self-targeting properties. Two new mannan conjugates, containing a gadolinium complex and a fluorescent probe, one based only on polysaccharide and the other one comprising polysaccharide with poly(2-methyl-2-oxazoline) grafts, were prepared and simultaneously visualized in vitro and in vivo by magnetic resonance and fluorescence imaging. The synthesis of these mannan-based complexes was based on alkylation with allyl bromide or grafting with poly(2-methyl-2-oxazoline) chains, followed by a thiol-ene click reaction with cysteamine to introduce primary amino groups into their structure. Finally, the obtained conjugates were functionalized with contrast labels using the corresponding N-hydroxysuccinimide esters. When used to detect lymph nodes, the polymers showed better imaging properties than a commercially available contrast agent.