Hurthle cell neoplasms of the thyroid: sonographic appearance and histologic characteristics.
OBJECTIVE
The purpose of this study was to determine the sonographic features of Hürthle cell neoplasms (HCNs) of the thyroid.


METHODS
We retrospectively analyzed the sonographic appearance of 15 histologically proven HCNs in 15 patients aged 16 to 70 years (mean age, 44 years). Sonographic features that were reviewed included the size and echogenicity of the tumors, the presence of cystic areas or calcifications, and detectable blood flow on color Doppler imaging. Correlation of sonographic findings with pathologic results was performed.


RESULTS
The tumors ranged from 0.4 to 7 cm in diameter, but most were less than 3 cm in diameter. Four (27%) of the 15 tumors were homogeneously hypoechoic. Two tumors (13%) were predominantly hypoechoic with isoechoic areas to thyroid parenchyma. Two (13%) neoplasms were isoechoic to thyroid parenchyma. Four (27%) tumors were predominantly isoechoic, containing hypoechoic areas, and 3 (20%) tumors were hyperechoic. Three neoplasms contained cystic components. None of the tumors contained calcifications. One tumor was avascular on Doppler examination. One neoplasm showed only peripheral blood flow. Thirteen tumors showed internal vascularity, 7 of them with peripheral blood flow. Twelve HCNs were benign, and 3 were malignant on pathologic examination.


CONCLUSIONS
Hürthle cell neoplasms show a spectrum of sonographic appearances from predominantly hypoechoic to hyperechoic lesions and from peripheral blood flow with no internal flow to extensively vascularized lesions. Pathologic criteria differentiating benign and malignant HCNs (absence or presence of a capsular breach, vascular or extrathyroidal tissue invasion, nodal involvement, and distant metastasis) are beyond the resolution of sonography and fine-needle aspiration biopsy and require removal of the entire lesion. This precludes diagnosis and characterization of HCNs by sonography.
Maizlin
Zeev V
ZV
Department of Radiology, McMaster University Medical Center, Hamilton ON L8N 3Z5, Canada. zeev25@yahoo.com
Wiseman
Sam M
SM
Vora
Parag
P
Kirby
John M
JM
Mason
Andrew C
AC
Filipenko
Douglas
D
Brown
Jacqueline A
JA
D018249:Adenoma, Oxyphilic / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000473:pathology; D003560:Cysts / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D050031:Hashimoto Disease / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000473:pathology; D013964:Thyroid Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000473:pathology; D013965:Thyroidectomy; D018615:Ultrasonography, Doppler, Color