CT features of small thyroid carcinoma / 中华放射学杂志

ABSTRACT

Objective To study the CT findings of small thyroid carcinoma. Methods The CT findings of 40 patients with histology-proven small thyroid carcinoma (diameter, 1.0 to 2. 0 cm) were retrospectively reviewed. Results (1)The single lesion was detected in 38 cases and two lesions in bilateral thyroid in 2 cases. Two cases were combined with contralateral nodular goiter and I case with contralateral thyroid adenoma. ( 2 ) Eight lesions showed smooth edge and complete envelope. Thirty-four lesions demonstrated foggy edge and incomplete envelope,but they didn't invade the surrounding soft tissues and important organs. ( 3 ) The density of all lesions were homogeneous or comparatively homogeneous without obvious hemorrhage or necrosis area on non-enhanced CT. Thirty lesions showed varied shape calcifications,with granular calcifications in 20 lesions being the most common. Irregular nodular,eggshell-like or mulberrylike calcifications were also detected. (4)Forty-one lesions showed marked enhancement on post-contrast CT and the amplitude of enhanced CT value was greater than 40 HU(range,90 to 140 HU). Thirty-eight lesions exhibited homogeneous enhancement, and other 3 lesions showed marked enhancement center with a ring-like low density edge and manifested as a characteristic damascene-like appearance. (5)Enlarged cervical lymph nodes were found in 24 cases ( 60. 0% ), which displayed solid, cystic-solid or cystic appearances on nonenhanced CT. They showed markedly homogeneous,irregular ring or wall-node enhancement on post-contrast CT. In 8 cases there were granular, nodular or eggshell-like calcifications within the enlarged lymph nodes.Conclusion A solid thyroid nodule with granular calcification, incomplete envelope and marked enhancement, companied with enlarged lymph nodes with calcification, cystic degeneration and obviously enhanced solid part are the relatively characteristic CT features of small thyroid carcinoma.