甲状腺实性小结节的超声与病理对照研究

 目的  分析甲状腺实性小结节(直径＜10 mm)的超声及病理学表现, 以提高超声定性诊断水平。  方法  对照分析50例甲状腺乳头状微小癌(papillary thyroid microcarcinoma,PTMC)和34例结节性甲状腺肿(nodular goiter,NG)的声像图表现,包括结节的位置、形态、大小、内部及后方回声、钙化、边界和血流情况,并与病理学表现相对照。  结果  PTMC多表现为低回声结节(89.3%),纵横比≥1(71.4%),伴有后方回声衰减(64.2%),可见微小钙化(37.5%);NG结节表现为中高回声(64.7%),纵横比＜1(73.5%),后方回声无衰减(88.2%)。良恶性结节的回声强度及后方回声、纵横比、微小钙化、形态、边界、血流阻力指数的差异有统计学意义。PTMC的病理基础为不同比例组成的癌细胞和纤维间质呈乳头状或滤泡状结构排列,可有纤维假包膜、砂粒体和肿瘤血管。NG的病理基础为形态规则,边界清晰,由大小不等滤泡结构组成,伴薄层纤维组织包裹分隔滤泡组织,滤泡腔内含多量胶质。  结论  PTMC和NG的病理构成差异决定其超声图像特征的不同。

Ultrasonography of small solid thyroid nodules correlates with pathology

Objective  To investigate ultrasound and pathologic findings of small solid thyroid nodules (＜10 mm) to improve the characterization of these nodules.  Methods  Ultrasonographic features of 50 patients with papillary thyroid microcarcinoma (PTMC) and 34 patients with nodular goiter (NG) proved by surgery and pathology were evaluated comparatively. These features included the location,shape and size of nodules, internal and rear echo, calcification, border and blood flow were correlated with pathology.  Results  PTMC frequently showed the hypoecho (89.3%), ratio of anteroposterior and transverse diameters (A/T) ≥1 (71.4%), rear echo attenuation (64.2%) and microcalcification (37.5%). In contrast, NG often were the iso- or hyperechoic nodules (64.7%) with A/T＜1 (73.5%) and no rear echo attenuation (88.2%). Significant differences between benign and malignant nodules were found in echo intensity, A/T, microcalcification, shape, border and blood flow resistance index.Pathologically, PTMC consisted of tumor cells and fibrous stroma arranged into the papillary or follicular structure,and often had the fibrous pseudocapsule, psammoma body and tumor angiogenesis. NG showed regular shape, clear border, and composed of follicular structure in different sizes and shapes, with thin fibrous tissue encasing and separating follicular tissue. The follicles filled with much colloid.  Conclusions  The differences of ultrasonographic features between PTMC and NG are determined by their underlying pathology.