Hashimoto thyroiditis: Part 2, sonographic analysis of benign and malignant nodules in patients with diffuse Hashimoto thyroiditis.
OBJECTIVE
The purpose of this article is to compare sonographic features of benign and malignant nodules in patients with diffuse Hashimoto thyroiditis.


METHODS
As part of an ongoing multiinstitutional study, patients who underwent ultrasound and fine-needle aspiration of one or more thyroid nodules were analyzed for a variety of predetermined sonographic features. Patients with a sonographic appearance consistent with diffuse Hashimoto thyroiditis and with coexisting nodules that could be confirmed to be benign or malignant by fine-needle aspiration or surgical pathologic analysis were included in the study.


RESULTS
Among nodules within diffuse Hashimoto thyroiditis, 84% (69/82) were benign (35 nodular Hashimoto thyroiditis, 32 nodular hyperplasia, and two follicular adenoma), and 16% (13/82) were malignant (12 papillary carcinoma and one lymphoma). Malignant nodules were more likely to be solid and hypoechoic (62% vs 19%). All types of calcifications were more prevalent among malignant nodules, including microcalcifications (39% vs 0%), nonspecific tiny bright reflectors (39% vs 6%), macrocalcifications (15% vs 3%), and eggshell (15% vs 2%). Benign nodules were more likely to be hyperechoic (46% vs 9%), to have a halo (39% vs 15%), and to lack calcifications (88% vs 23%). Benign nodules more often had ill-defined margins (36% vs 8%).


CONCLUSIONS
Sonographic features of benign and malignant nodules within diffuse Hashimoto thyroiditis are generally similar to the features typical of benign and malignant nodules in the general population. If calcifications of any type are added to the list of malignant sonographic features, the decision to biopsy a nodule in patients with diffuse Hashimoto thyroiditis can be based on recommendations that have been published previously.
Anderson
Lauren
L
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Middleton
William D
WD
Teefey
Sharlene A
SA
Reading
Carl C
CC
Langer
Jill E
JE
Desser
Terry
T
Szabunio
Margaret M
MM
Mandel
Susan J
SJ
Hildebolt
Charles F
CF
Cronan
John J
JJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D005260:Female; D050031:Hashimoto Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D018608:Ultrasonography, Doppler / Q000379:methods*