Atypia of undetermined significance and follicular lesions of undetermined significance: sonographic assessment for prediction of the final diagnosis.
OBJECTIVE
To determine whether radiologic assessment of thyroid nodules can potentially help guide clinical management after a cytologic diagnosis of atypia of undetermined significance or a follicular lesion of undetermined significance.


METHODS
We identified 41 patients with 41 thyroid nodules initially diagnosed as atypia or follicular lesions of undetermined significance on fine-needle aspiration that were subsequently definitively diagnosed by either surgical resection or repeated fine-needle aspiration. All sonograms of nodules were reviewed by 2 blinded board-certifiedradiologists. Lesions were assessed in 3 ways: (1) Mayo pattern classification as benign, indeterminate, or worrisome for malignancy (Ultrasound Q 2005; 21:157-165); (2) thyroid imaging reporting and data system scores (scale of 1-5) based on 2 different previously published scoring criteria (Park et al [Thyroid 2009; 19:1257-1264] and Kwak et al [Radiology 2011; 260:892-899]); and (3) binary classification as benign or malignant.


RESULTS
Of the 41 nodules, 25 had benign histologic findings, and 16 were malignant. Mayo pattern classification was 100% accurate for the benign score. Lesions with a Mayo score of indeterminate were malignant in 21% of cases (6 of 28) and benign in 79% (22 of 28). Lesions with a Mayo score of malignant were malignant in 91% of cases (10 of 11) and benign in 9% (1 of 11). Thyroid imaging reporting and data system scores had area under the receiver operating characteristic curve values of 0.827 for Park scores and 0.822 for Kwak scores. Radiologist binary classification of thyroid nodules showed 88% overall accuracy.


CONCLUSIONS
Radiologist assessment of thyroid nodules in cases of atypia of undetermined significance or follicular lesions of undetermined significance is highly predictive of the final diagnosis and can help guide management of thyroid nodules of these pathologic types.
Departments of Radiology (A.K., T.S.D.), Pathology (G.H.L., C.K.), and Medicine and Endocrinology (H.A.), Stanford University Medical Center, Stanford, California USA; and Department of Biomedical Informatics, Stanford University, Stanford, California USA (Y.L.). kamaya@stanford.edu.
Aya
A
Kamaya
Departments of Radiology (A.K., T.S.D.), Pathology (G.H.L., C.K.), and Medicine and Endocrinology (H.A.), Stanford University Medical Center, Stanford, California USA; and Department of Biomedical Informatics, Stanford University, Stanford, California USA (Y.L.).
Gloria Huang
GH
Lewis
Departments of Radiology (A.K., T.S.D.), Pathology (G.H.L., C.K.), and Medicine and Endocrinology (H.A.), Stanford University Medical Center, Stanford, California USA; and Department of Biomedical Informatics, Stanford University, Stanford, California USA (Y.L.).
Yi
Y
Liu
Departments of Radiology (A.K., T.S.D.), Pathology (G.H.L., C.K.), and Medicine and Endocrinology (H.A.), Stanford University Medical Center, Stanford, California USA; and Department of Biomedical Informatics, Stanford University, Stanford, California USA (Y.L.).
Haruko
H
Akatsu
Departments of Radiology (A.K., T.S.D.), Pathology (G.H.L., C.K.), and Medicine and Endocrinology (H.A.), Stanford University Medical Center, Stanford, California USA; and Department of Biomedical Informatics, Stanford University, Stanford, California USA (Y.L.).
Christina
C
Kong
Departments of Radiology (A.K., T.S.D.), Pathology (G.H.L., C.K.), and Medicine and Endocrinology (H.A.), Stanford University Medical Center, Stanford, California USA; and Department of Biomedical Informatics, Stanford University, Stanford, California USA (Y.L.).
Terry S
TS
Desser
D018263:Adenocarcinoma, Follicular / Q000145:classification / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016606:Thyroid Nodule / Q000145:classification / Q000175:diagnosis*; D014463:Ultrasonography / Q000379:methods*
Bethesda category III; atypia of undetermined significance; follicular lesion of undetermined significance; head and neck ultrasound; thyroid nodule