Ultrasonography Classification of the American Thyroid Association for Predicting Malignancy in Thyroid Nodules >1cm with Indeterminate Cytology: A Prospective Study

Abstract

The objective of this prospective study was to evaluate the ultrasonography classification of the American Thyroid Association (ATA) for predicting malignancy in thyroid nodules >1 cm with indication for fine-needle aspiration (FNA) whose cytology was indeterminate. Additionally, the combination of the ATA classification with Doppler analysis was evaluated. All patients with thyroid nodules >1 cm were eligible. Each nodule was assigned to one of the ATA categories. Exclusively or predominantly intranodular vascularity was considered suspicious. One hundred and thirty-seven patients with 143 nodules underwent FNA and those with indeterminate cytology (Bethesda category III or IV) were selected. All patients were referred for surgery. Among the 143 nodules evaluated, 92 were benign, 33 were malignant, 13 were noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP), and 5 were tumors of uncertain malignant potential (TUMP). The rate of malignancy, including NIFTP and TUMP in this definition, was 80%, 42.8%, 13%, 10%, and 23% for nodules with a high suspicion, intermediate suspicion, low suspicion, very low suspicion, and undefined ultrasonographic pattern, respectively. Considering NIFPT and TUMP as benign, these rates were 72%, 22.4%, 4.3%, 0%, and 15.4%, respectively. The addition of Doppler analysis did not significantly improve the prediction of malignancy obtained with the ATA classification alone. The results of this prospective study show the usefulness of the ATA ultrasonographic classification for predicting malignancy specifically in thyroid nodules >1 cm with indeterminate cytology. The ATA category of the nodule should influence the decision for follow-up, molecular tests, or surgery.

Active Surveillance in Adults with Low-Risk Papillary Thyroid Microcarcinomas: A Prospective Study

“…Among adults ≥ 20 years with nodules ≤ 1.2 cm who were submitted to FNA but excluded from the study because cytology was not suspicious or diagnostic of PTC, 21 patients had highly suspicious nodules on US [1] and Bethesda cytology I (on two occasions), III (on two occasions), or IV. In these situations (combination of US and FNA), the risk of malignancy exceeds 50 % in our experience [13][14][15][16], and the patients were also followed up by US every 6 months. The number of biannual evaluations (after initial assessment) was 6 in 5 patients, ≥ 5 in 7, ≥ 4 in 10, ≥ 3 in 12, ≥ 2 in 15, and ≥ 1 in 21.…”

Extending expressed RNA genomics from surgical decision making for cytologically indeterminate thyroid nodules to targeting therapies for metastatic thyroid cancer

“…Consequently, even with ultrasound and cytological examination, the character of thyroid nodules remains uncertain in approximately 1 in 7 thyroid patients. When a cytologically indeterminate nodule has been identified by an expert cytopathologist, doubt exists that the risk of cancer can be sufficiently reduced to avoid surgery through repeat biopsy, review by a second cytopathologist, further subclassification of the indeterminate category, or correlation with thyroid nodule ultrasound classification …”

Thyroid imaging reporting and data system (TI‐RADS) of the American College of Radiology (ACR) for predicting malignancy in thyroid nodules >1 cm with indeterminate cytology

“…As reported previously, 112 of the 137 patients included were women, ranging in age from 18 to 71 years. The concentrations of TSH ranged from 0.6 to 5 mIU/L.…”

“…In addition to evaluating the ACR TI‐RADS specifically in nodules with indeterminate cytology, the results reported here are derived from a prospective study, only nodules with an indication for FNA were included, all patients with category III cytology underwent FNA repetition, histology was obtained in all cases, and the rate of malignancy was reported with and without exclusion of NIFTP and TUMP …”

“…Despite similar sensitivity and specificity, in contrast to the ATA classification in which 13/143 nodules (9%) did not meet the criteria for any of the categories and had a risk of malignancy of 15%, all nodules were now classified using the ACR TI‐RADS. Our results show the usefulness of the ACR TI‐RADS for predicting malignancy specifically in thyroid nodules greater than 1 cm with indeterminate cytology.…”