原发性肾脏罕少见良性肿瘤的CT、MRI 表现与临床病理分析

目的：分析和探讨肾脏罕少见良性肿瘤的 CT、MRI 影像学表现及临床病理分析,提高肾脏罕少见良性肿瘤的诊断准确性。方法回顾性分析本院9例经手术及病理证实的肾脏罕少见良性肿瘤的 CT 及 MRI 影像学资料,分析其影像学特点和病理特征。结果入组病例分别为混合型上皮间质肿瘤(MESTK),囊性肾瘤(CN),平滑肌瘤(RL),嗜酸细胞腺瘤(RO)。病变分布情况：6例位于左肾,3例位于右肾。瘤体大小：长径2.5~8.9 cm,平均5.7 cm；短径2.5~8.4 cm,平均4.9 cm。形态：类圆形或椭圆形(n=7),不规则形(n=2)。9例病灶突出于肾轮廓外。MESTK 呈多囊性病变,增强扫描囊性成分未见明确强化,囊壁及粗间隔可见强化。CN 呈囊性病灶,平扫可见斑片状钙化,增强扫描囊性成分未见明确强化,病灶可见强化分隔影。RL 的 CT 和 MRI 平扫密度/信号不均匀,可见斑片状坏死；病灶增强扫描皮质期及髓质期明显强化,延迟期强化程度减退。RO 1例 MRI 平扫 T1 WI 呈不均匀低信号；T2 WI 呈不均匀高信号；CT 病灶密度欠均匀,平扫以等密度为主；增强扫描皮质期、髓质期病变呈明显不均匀强化,排泄期强化程度下降,中心瘢痕可见轻度延迟强化。结论肾脏罕少见良性肿瘤具有一定的 CT、MRI 影像学特点,结合其临床病理特点,可以提高肾脏罕少见恶性肿瘤的诊断和鉴别诊断。

CT/MRI features and pathological analysis of primary renal rare benign tumors

Objective To improve the diagnostic accuracy of primary renal rare benign tumors by exploring and analyzing the CT/MRI and clinical pathologic features.Methods 9 patients with primary renal rare benign tumors pathologically proven lesions after operation who had CT or MRI exams with contrast were enrolled in our hospital.The radiological and clinical pathological features of all tumors were analyzed respectively.Results The cases were the mixed epithelial and stromal tumor of kidney (MESTK),cystic nephroma(CN),renal leiomyoma(RL)and renal oncocytoma(RO)respectively.Location:6 cases were in left kidney and 3 in right kidney.Size:long diameter 2.5-8.9 cm,mean 5.7 cm;short diameter 2.5-8.4 cm,mean 4.9 cm.The tumor shape included oval(n=7) and irregular(n=2).9 cases protruded from the renal surface.MESTK showed polycystic lesions on preconstrast,various degrees of cystic wall and septum enhancement were detected on enhancement scans.CN showed cystic lesions and calcification on preconstrast, slight septum enhancement were detected on enhancement scans.RL showed heterogeneous density or signal with patchy necrosis and clear border on precontrast,the obvious enhancement was found on cortex and medullary phase and slight washout enhancement was detected on excretory phase.RO showed heterogeneous hypointense on T1 WI,hyperintense on T2 WI and mixed isodensity and hypodensity on CT precontrast.Slight delayed enhancement was found in central scar and washout enhancement was detected in parenchyma on three phases.Conclusion There are some special CT/MRI characteristics for primary renal rare benign tumors,which could improve their diagnosis and differential diagnosis combined with the clinical pathological features.