甲状腺内胸腺癌声像图特征及临床病理特点分析

Ultrasonographic and clinical pathological features of intrathyroid thymic carcinoma

目的探讨甲状腺内胸腺癌(intrathyroid thymic carcinoma,ITTC)的声像图特征及临床病理特点。方法回顾性分析经病理证实的11例ITTC的声像图特征及临床病理特点,记录病灶的大小、形态、边界、内部回声、钙化、囊变、病灶血流及颈部淋巴结情况,对病灶进行TI-RADS分类,同时记录患者病史、临床症状及治疗过程。结果11例ITTC患者病灶均为实性,位于甲状腺下极或中下部分,8例位于甲状腺右叶(8/11,72.7%),3例位于甲状腺左叶(3/8,27.3%),病灶最大径线为(3.55±0.51)cm,回声均为低回声或极低回声,边界不清晰。病灶内部回声不均匀,10例肿物内部可见线样高回声。TI-RADS分类为4a类2例,4b类3例,4c类2例,5类4例。所有病灶中未出现钙化及囊性区,纵横比均<1。11例中3例同时伴有桥本甲状腺炎。手术后病理显示5例出现颈部淋巴结转移,5例侵犯周围软组织,其中3例侵犯喉返神经,2例侵犯食管壁,3例侵犯颈部横纹肌。免疫组化显示所有病灶CD5及CD117均为阳性。患者均行手术治疗,其中3例术后进行了放疗与化疗。结论ITTC有共同的声像图特征,位于甲状腺下极或者中下,呈实性低回声或极低回声,边界不清,其内可见线样高回声,这些声像图特征有助于ITTC的诊断。

Objective To investigate the ultrasonographic and clinical pathological features of intrathyroid thymic carcinoma(ITTC). Methods The ultrasonographic and clinical pathological features of 11 cases of pathologically confirmed intrathyroid thymic carcinoma were analyzed retrospectively. The size, shape, boundary, internal echo, calcification, cystic change, blood flow of the lesion and lymph nodes of the neck were recorded. TI-RADS classification was performed on the lesion, and the medical history, clinical symptoms and treatment process of the patients were recorded. Results The lesions of all 11 patients were solid and located in the lower pole or middle-lower part of the thyroid, 8 cases were located in the right lobe of the thyroid gland (8/11, 72.7%), and 3 cases were located in the left lobe (3/8, 27.3%). The maximum diameter diameter of the lesions was (3.55±0.51)cm. All the lesions were hypoechogenicity or marked hypoechogenicity and ill-defined margin. The internal echo of the lesions were heterogeneous. Ten lesions were characterized by striped hyperechogenicity interiorly on ultrasonograms. According to TI-RADS classification, 2 cases were class 4a, 3 cases were class 4b, 2 cases were class 4c and 4 cases were class 5. There was no cystic component or calcifcation in all lesions, and there was no taller-than-wide shape. Three of 11 cases were accompanied by Hashimoto′s thyroiditis. Postoperative pathology showed that 5 cases had cervical lymph node metastasis, 5 had perithyroidal soft tissue in ltration, of them, 3 cases had recurrent laryngeal nerve, 2 cases invaded the esophageal wall, and 3 cases invaded the striated muscle of the neck. Immunohistochemistry showed that CD5 and CD117 of all lesions were positive. All patients underwent surgery, and 3 of them underwent radiotherapy and chemotherapy after surgery. Conclusions There are common sonographic features of intrathyroid thymic carcinoma, which are located at the lower pole or middle-lower of the thyroid gland, presenting a solid hypoechogenicity or marked hypoechogenicity, with ill-defined margin and striped hyperechogenicity interiorly on ultrasonograms. These sonographic features are helpful for the diagnosis of ITTC.