Heterogeneous echogenicity of the thyroid parenchyma does not influence the detection of multi-focality in papillary thyroid carcinoma on preoperative ultrasound staging

Preoperative Staging of Differentiated Thyroid Carcinomas: Comparison of USG and CT with Intraoperative Findings and Histopathology

To study the efficacy of USG and CECT in preoperative staging of differentiated thyroid carcinomas in comparison to the intraoperative and histopathological findings. A prospective, observational study was conducted in a tertiary care hospital over a period of one and a half years where USG and CECT of 23 subjects with histopathologically proven differentiated thyroid malignancy were analysed to study the characteristics of the primary tumour, lymphatic metastasis and evaluate the sensitivity and specificity of the radiological investigations in comparison to the intra-operative and histopathological findings. When compared with intraoperative and histopathological T-staging, USG had an accuracy of 69.5% and 73.9% and CECT had an accuracy of 78.2% and 73.9% respectively. The sensitivity and specificity of USG and CECT in determining a malignant nodule was 71.4% and 33.3% and 52.4% and 66.7% respectively. The N-staging according to the histopathological examination findings was in agreement with that of USG in 65.2% and CECT in 65.2% patients. The sensitivity and specificity of USG was 94.4% and 41.7% and that of CECT was 92.2% and 44.4% respectively in detecting lymphatic metastasis. The sensitivity and specificity of USG was 94.4% and 44.4% and that of CECT was 92.2% and 27.3% respectively in detecting lateral compartment lymphatic metastasis. USG identifies the characteristics of the malignant nodules better and CECT has a higher identifying central compartment lymphatic metastasis. CECT should be used as an adjunct to ultrasound to determine the extent of lymphatic metastasis and staging of disease.

Updated guidelines on the preoperative staging of thyroid cancer

Recent studies have provided prognostic information and recommendations for staging thyroid cancers that have changed the staging and management guidelines for the disease. Consequently, minimal extrathyroidal extension (ETE) was removed from the T3 stage classification in the eighth edition of the TNM staging system by the American Joint Committee on Cancer. New T categories have been subsequently added, including T3a, defined as a tumor >4 cm in its greatest dimension, limited to the thyroid gland, and T3b, defined as a tumor of any size with gross ETE invading only the strap muscles. In this article, the author reviews the changes in the TNM staging system for thyroid cancer, with an emphasis on ultrasonography in preoperative staging.

A Modified Thyroid Imaging Reporting and Data System (mTI-RADS) For Thyroid Nodules in Coexisting Hashimoto's Thyroiditis

To develop a conventional ultrasound (US) modified Thyroid Imaging Reporting and Data System (mTI-RADS) to stratify the malignancy risk of thyroid nodule in coexisting Hashimoto’s thyroiditis (HT). The study included 138 malignant and 292 benign thyroid nodules confirmed by cytological or histopathological results. The risk score (RS) for each significant US feature was estimated by multiplying corresponding regression coefficient and the total score for each nodule was defined as the sum of these individual scores. The mTI-RADS was established according to the total RS and divided into category 3, 4a, 4b, 4c and 5. Marked hypoechogenicity, taller-than-wide shape, poorly-defined margin, microcalcification or macrocalcification and halo sign absence were statistically significant US features in prediction of thyroid malignancy (all p < 0.05). The total RS for each nodule was defined as following: RS = 2.1× (if marked hypoechogenicity) + 1.2× (if taller-than-wide shape) + 1.7× (if no halo sign) + 0.6× (if poorly-defined margin) + 1.2× (if microcalcification or macrocalcification). The malignancy rates in mTI-RADS category 3, 4a, 4b, 4c and 5 nodules were 3.7%, 19.3%, 38.1%, 62.7% and 94.1%, respectively, with significant differences among different categories (P < 0.001). The mTI-RADS category may facilitate subsequent treatment management in HT patients.

Pathologic spectrum of lymphocytic infiltration and recurrence of papillary thyroid carcinoma

PURPOSE

The aim of this study was to investigate the prognosis of papillary thyroid carcinoma (PTC) patients according to different pathologic grades of lymphocytic thyroiditis (LT).

MATERIALS AND METHODS

This study included 144 PTC patients who underwent total thyroidectomy with radioactive iodine remnant ablation therapy. Pathologic grades of LT were separated at two points, chronic lymphocytic thyroiditis (CLT) and Hashimoto thyroiditis (HT). Patients were divided into two groupings according to the presence of the diseases (Grouping 1; patients with CLT or HT and without CLT or HT, Grouping 2; patients with HT and without HT). The groupings were compared according to recurrence, clinicopathologic and ultrasound (US) characteristics, and disease free survival.

RESULTS

Of 144 patients, 41 had CLT and 19 had HT. There were 10 patients (6.9%) with tumor recurrence. In both groupings, the presence of calcification was more frequently associated with patients with LT (p=0.041 and 0.047, respectively). In Grouping 2, the mean age at diagnosis was older in patients without HT compared to patients with HT (p=0.032). On multivariate analysis, the presence of LT was not an independent predictor of recurrence in both groupings. For both groupings, pathologic tumor size and taller than wide shape on US were independent predictors of recurrence. The presence of LT in PTC patients did not affect recurrence.

CONCLUSION

There was no relationship between PTC prognosis and different grades of LT. Pathologic tumor size and taller than wide shape on ultrasound were independent predictors of PTC recurrence regardless of concurrent LT.