小甲状腺癌的CT表现分析

目的 分析小甲状腺癌的CT表现,探讨其CT征象.方法 对40例CT平扫及增强扫描后经手术病理证实的直径在1.0～2.0 cm的小甲状腺癌的CT表现进行回顾性分析.结果 (1)38例为单发癌灶,2例为双侧双发癌灶;2例合并对侧结节性甲状腺肿,1例合并对侧甲状腺腺瘤;(2)边缘光整,包膜完整者8个病灶;边缘不光整,包膜不完整者34个病灶,但未见明显周围软组织及重要器官侵犯;(3)病灶平扫密度均匀或较均匀,未见明显出血或坏死囊变区;病灶内伴钙化者30个病灶,钙化形态各异,以砂粒状多见(20个病灶),也可见不规则结节状、蛋壳状或桑椹状钙化;(4)增强后41个病灶明显强化(强化幅度＞40 HU,CT值在90～140 HU之间),其中38个病灶均匀强化,3个病灶中央强化明显,边缘可见一环形低密度影,呈镶嵌征;(5)伴颈部淋巴结肿大者24例(60.0%),可呈实性、囊实性或囊性,增强后可呈均匀明显强化、不规则环形强化或壁结节样强化;8例淋巴结内可见砂粒状、结节状或蛋壳状钙化.结论 砂粒状钙化、甲状腺包膜不完整、强化明显的甲状腺实性结节及伴钙化、囊变、实性部分明显强化的颈部肿大淋巴结为小甲状腺癌较为特征性的CT表现.

CT features of small thyroid carcinoma

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.