Table 4.
Unclassifiable follicular thyroid neoplasms according to the ultrasound-based malignancy risk stratification systems
| Nodule ID | Pathological diagnosis | Ultrasound description | Maximum diameters (cm) | Unclassified by | |||||
|---|---|---|---|---|---|---|---|---|---|
| ATA | AACE/ACE/AME | K-TIRADS | EU-TIRADS | ACR-TIRADS | C-TIRADS | ||||
| 4 | FTC (minimally invasive) | Solid, hypoechoic, ill-defined margin, irregular shape, macrocalcifications | 1.7 | X | X | ||||
| 23 | FTC (minimally invasive) | Solid, hypoechoic, ill-defined margin, round to oval shape, peripheral halo | 2.7 | X | X | ||||
| 33 | FTC (minimally invasive) | Solid, isoechoic, smooth margin, round to oval shape, microcalcififications, peripheral halo | 2.7 | X | |||||
| 35 | FTC (minimally invasive) | Solid, isoechoic, ill-defined margin, irregular shape, peripheral calcifications, peripheral halo | 4.1 | X | |||||
| 36 | FTC (widely invasive) | Solid, hypoechoic, ill-defined margin, irregular shape | 4.7 | X | |||||
| 38 | FTC (minimally invasive) | Solid, isoechoic, ill-defined margin, round to oval shape, microcalcififications, peripheral halo | 2.9 | X | |||||
| 39 | FTC (widely invasive) | Composition cannot be determined because of macrocalcifications, present a suspicious cervical lymph node | Undetermined because of macrocalcifications | X | X | ||||
| 41 | FTC (minimally invasive) | Solid, hypoechoic, smooth margin, irregular shape, peripheral halo | 2.0 | X | |||||
| 42 | FTC (minimally invasive) | Solid, hyperechoic, smooth margin, round to oval shape, microcalcififications, peripheral halo | 3.0 | X | |||||
| 44 | FTC (widely invasive) | Solid, isoechoic, ill-defined margin, round to oval shape | 2.4 | X | |||||
| 46 | FTC (minimally invasive) | Solid, hypoechoic, ill-defined margin, round to oval shape, macrocalcifications, peripheral halo | 2.7 | X | X | ||||
| 49 | FTC (encapsulated angioinvasive) | Solid, isoechoic, ill-defined margin, round to oval shape, peripheral halo | 12.1 | X | |||||
| 61 | FTC (encapsulated angioinvasive) | Solid, isoechoic, ill-defined margin, round to oval shape, macrocalcifications | 5.7 | X | |||||
| 94 | FTC (minimally invasive) | Solid, hypoechoic, smooth margin, irregular shape | 5.7 | X | |||||
| 73 | FTA | Solid, isoechoic, ill-defined margin, round to oval shape, macrocalcifications | 9.0 | X | |||||
| 74 | FTA | Solid, isoechoic, ill-defined margin, irregular shape, microcalcififications | 2.0 | X | |||||
| 81 | FTA | Composition cannot be determined because of peripheral calcifications | 4.4 | X | X | X | |||
| 210 | FTA | Solid, hypoechoic, ill-defined margin, round to oval shape | 0.8 | X | X | ||||
| 223 | FTA | Mixed, isoechoic, ill-defined margin, round to oval shape, macrocalcifications, peripheral halo | 2.8 | X | |||||
| 241 | FTA | Solid, isoechoic, smooth margin, round to oval shape, microcalcifications, peripheral halo | 2.5 | X | |||||
| 254 | FTA | Solid, hypoechoic, ill-defined margin, round to oval shape | 1.1 | X | X | ||||
| 275 | FTA | Mixed, isoechoic, smooth margin, round to oval shape, microcalcifications | 2.9 | X | |||||
| 284 | FTA | Solid, hypoechoic, ill-defined margin, irregular shape | 3.5 | X | X | ||||
| 293 | FTA | Solid, hypoechoic, ill-defined margin, round to oval shape, peripheral calcifications | 1.1 | X | X | ||||
| 295 | FTA | Solid, isoechoic, ill-defined margin, round to oval shape, microcalcifications | 0.7 | X | |||||
| 313 | FTA | Solid, hypoechoic, ill-defined margin, round to oval shape | 1.1 | X | X | ||||
| 324 | FTA | Mixed, isoechoic, smooth margin, round to oval shape, microcalcifications | 4.1 | X | |||||
A nodule was undetermined composition without any high-risk features, which could not be classified according to 2015 ATA, AACE/ACE/AME and K-TIRADS
A nodule was undetermined composition with a suspicious cervical lymph node, which could not be classified according to 2015 ATA and K-TIRADS
Six nodules were irregular shape without any high-risk features, which could not be classified according to AACE/ACE/AME
Eight nodules were iso/hyperechoic with microcalcification, which could not be classified according to 2015 ATA
Eight solid nodules were hypoechoic with ill-defined margin, which could not be classified according to 2015 ATA
Eleven nodules were ill-defined margin without any high-risk features, which could not be classified according to EU-TIRADS
Abbreviations: FTA follicular thyroid adenoma; FTC follicular thyroid carcinoma; ATA 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer; AACE/ACE/AME American Association of Clinical Endocrinologists, American College of Endocrinology, and Associazione Medici Endocrinology Medical Guidelines for Clinical Practice for the Diagnosis and Management of Thyroid Nodules (2016 Update); EU-TIRADS European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules in Adults; K-TIRADS Revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations; ACR-TIRADS American College of Radiology Thyroid Imaging Reporting and Data System; C-TIRADS 2020 Chinese Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules