甲状腺未分化癌的CT表现与病理对照分析

CT Findings and Pathological Analysis of Anaplastic Thyroid Carcinoma

目的 分析甲状腺未分化癌（ATC）的CT表现,并与病理对照,以提高对该少见疾病的认识。方法 回顾性分析经病理证实的20例ATC患者的CT资料。男7例,女13例,年龄22-81岁,平均65.5岁。对肿瘤的部位、大小、形态、边缘、CT密度及强化形式进行分析,并与病理结果相对照。结果 20例患者中,单侧18例,双侧2例,2例峡部同时受累,共22个病灶。合并结节性甲状腺肿7例,腺瘤性增生1例;肿瘤最大径1.2-8.6 cm,平均（5.2±0.7）cm;病灶呈圆形或类圆形8个,不规则形14个;边缘光整者5个,边缘不光整者17个;6个病灶甲状腺轮廓连线完整,16个病灶出现甲状腺轮廓连线中断,肿瘤呈横向生长,纵横比〈1,其中6个侵犯食管,4个侵犯气管,4个侵犯颈前肌群,2个包绕同侧颈总动脉。CT平扫病灶呈低密度17个,等密度5个;密度均匀6个,不均匀16个;5个病灶内见钙化,以细颗粒状钙化多见（3个病灶）;增强后病灶呈明显强化15个,中度强化5个,轻度强化2个。14例伴颈部淋巴结肿大,增强扫描呈环形强化。结论 侵袭性生长、纵横比〈1、钙化少见、易坏死囊变、明显强化的甲状腺区肿块及伴有多区分布、环形强化的颈部肿大淋巴结可以提示ATC的诊断,其影像学表现与肿瘤的病理特征相关,CT检查可以准确显示病灶的范围和淋巴结转移情况,为临床制订治疗方案提供重要依据。

Methods To investigate the CT and pathological findings of anaplastic thyroid carcinoma and improve the recognition of this rare disease. Methods The CT characteristics of 20 patients （7 males, 13 females, median age 65.5 years old）with pathologically proven ATC were reviewed retrospectively. CT images were evaluated in relation to the following： location, size, morphology,margin, CT density, enhancement pattern and correlation with pathology. Results There were a total of 22 lesions in 20 patients. A single lesion was detected in 18 cases, two lesions in bilateral thyroid disease in 2 cases. Seven cases were combined with nodular goiter and 1 case with thyroid adenoma. The maximum diameter of the lesions ranged from 1.2 to 8.6 cm. Of the 22 lesions,8 were round or oval-round and 14 were irregular, 5 lesions showed smooth edges and 17 lesions demonstrated ill-defined edges. 6 lesions manifested a continuous contour and 16 lesions displayed an interrupted contour of the thyroid with transverse tumor growth and anteroposterior-to-transverse diameter ratio less than 1. Among them, the esophagus was invaded in six lesions, the trachea and the ipsilateral cervical muscle were invaded in four lesions respectively, the ipsilateral carotid artery was invaded in two lesions. 17 lesions displayed low-density and 5 lesions manifested isodensity on non-enhanced CT. 5 lesions showed calcifications, with granular calcifications in 3 lesions being the most common. The densities were homogeneous in 6 lesions and heterogeneous in 16 lesions,After intravenous injection of contrast media, 15 lesions demonstrated remarkable enhancement,5 lesions demonstrated moderate enhancement and 2 lesions demonstrated mild enhancement. Enlarged cervical lymph nodes were found in 14 cases,which displayed ring-like enhancement on post contrast CT. Conclusion Infiltrative thyroid masses with rare calcification, anteroposterior-to-transverse diameter ratio less than 1, cystic degeneration or necrosis and marked enhancement, accompanied by ring-like enhancement of cervical lymph nodes can indicate the diagnosis of ATC. Its imaging findings were correlated with pathology. CT exami- nations can accurately demonstrate the extent of tumor involvement, lymph node metastasis and are helpful to provide more comprehensive information for clinical management.