肾集合管癌:螺旋CT动态增强表现

目的:探讨肾集合管癌的影像学表现及其血液动力学特征与病理的关系,以提高诊断准确性。方法:经手术病理证实的肾脏集合管癌5例,术前行CT平扫及双期(皮髄交界期和实质期)增强扫描。回顾性分析其CT表现并与手术病理结果进行对比。结果:5例肿瘤形态不规则,境界欠清,肾脏轮廓基本正常。肿瘤直径4.0~13.5cm,平均7.3cm。2例肿瘤累及皮质-髓质,3例累及肾皮质-髓质-肾盂。3例肿瘤呈实质性,内可见小区域坏死;2例肿瘤呈囊实性,内可见很不规则液性低密度区。肿瘤实质部分平扫CT值17.1~36.8HU,平均27.4HU;动态增强扫描皮髓交界期其CT值为27.4~53.5HU,平均38.7HU;实质期CT值36.0~74.2HU,平均47.6HU。1例可见斑点状和针尖状钙化。腹膜后淋巴结转移2例,肺转移1例。结论:肾集合管癌的CT表现有一定特征性,表现为肿瘤较小时位于肾髓质,较大时位于肾脏中央区,形态极不规则,境界不清,患肾轮廓基本正常;动态增强扫描示肿瘤呈中等程度渐进性延迟强化,淋巴结和远处转移常见。

Dynamic Spiral CT Findings of Renal Collecting Duct Carcinoma

Objective:To study the imaging findings,the hemo-dynamic characteristics of renal collecting duct carcinoma,and to correlate with pathology,in order to improve the diagnostic accuracy.Methods:5 cases with surgery and pathology proved collecting duct carcinoma of kidney underwent spiral CT plain scan,post-contrast cortico-medullary phase and nephrographic phase scans before surgery.The CT features were reviewed and analysed retrospectively,correlation with surgical and pathological findings was also studied.Results:All of the 5 tumors were irregular in shape and ill-defined,with the mean diameter as 7.3cm (ranged from 4.0cm to 13.5cm).The renal contour of these 5 cases were basically normal.Tumor involved renal cortex and medulla (n=2),renal cortex and medulla as well as renal pelvis (n=3).Tumor mass was solid with small area of necrosis (n=3) and solid with cystic change with irregular hypo-attenuated fluid component (n=2).The CT value of the solid component on plain scan images was 17.1~36.8HU (mean=27.4HU).After contrast enhancement,the CT value of tumor on cortico-medullary phase images and nephrographic phases images were 27.4~53.5HU (mean=38.7HU) and 36.0~74.2HU (mean= 47.6HU) respectively.Spotted and punctate calcifications were found in 1 case,retroperitoneal lymph node metastases in 2 cases and pulmonary metastases in 1 cases.Conclusion:The CT characteristics of renal collecting duct carcinoma included:small tumor located within renal medulla,large tumor located within central part of kidney,with basically normal renal contour,markedly irregular in shape,ill-defined,masses with mild or moderate degree enhancement,which were progressively enhanced in the delayed phase,lymph node and distal metastases could often be revealed.