肾脏转移瘤与肾原发癌CT表现的对比研究

CT findings of metastastic and primary neoplasms of the kidney: a comparative study

目的探讨肾转移瘤的ＣＴ表现特点。方法对比分析经手术病理证实的１１例肾转移瘤及１００例原发肾癌的ＣＴ资料。转移瘤来自肺癌者６例，食管癌２例，肾上腺皮质癌、睾丸精原细胞瘤和原发灶不明各１例。结果肾转移瘤占同期肾恶性肿瘤的３．７％，与第二原发癌之比为１∶１。ＣＴ表现：肾转移瘤多呈浸润生长，无边界（６３．６％），少外凸（８１．８％），增强后无明显强化（１００％），肾盂呈浸润受侵（７２．７％），多灶性（１８．２％）。肾原发癌呈局限结节、块状、不规则形明显外凸（８７．０％），边界清楚，增强后有明显强化（８０．７％），常伴有明显坏死（６０．２％），可伴有钙化（１５．０％）或血管瘤栓（７．０％）。结论增强ＣＴ扫描有助于区别肾转移瘤与原发肾癌。具有典型征象的肾转移瘤能够与原发肾癌区别，而肿瘤单发、边界清、外凸生长、增强后有强化时不能与原发癌区别，尚需组织学诊断。

Objective To study CT findings of renal metastases and compare them with primary renal cell carcinoma. Methods CT features of eleven cases of renal metastases and one hundred cases of primary renal cell carcinoma confirmed by histopathology were studied and compared. The metastastic tumors arised from lung carcinoma in 6 cases, esophagus carcinoma in 2 cases and one in each of adrenal cortical carcinoma, testis seminoma and unknown primary tumor. Results Renal metastases accounted for 3.7% of all malignant tumors of the kidney. The ratio of renal metastases to second primary renal carcinoma was 1∶1. On CT, the renal metastases appeared as diffusely invasive, ill definded mass (63.6%), 18.2% of the neoplasms were multiple, without or less exophytic (81.8%) and without or with minimal enhancing on postcontrast scan (100%). The tumor invaded the pelvocalyceal system (72.7%). In contrast, the primary renal cell carcinomas were nodular, rounded or lobulated and more exophytic mass with well defined border and regular contours (87.0%). Moderate to high enhancing postcontrast (80.7%) was observed with obvious necrosis (60.2%), foci of calcification (15.0%) and invasion of the renal vein and inferior vena cava (7.0%). Conclusion Contrast enhanced CT is helpful in the differential diagnosis of renal metastases from primary renal cell carcinoma. But for those showing single, more exophytic mass with well defined border and intense enhancing postcontrast, the correct diagnosis depends on histopathology.