肾嗜酸细胞瘤的CT表现

目的探讨嗜酸细胞瘤（renaloncocytoma，RO）的CT表现并分析误诊原因，以提高对其诊断的准确性。方法回顾性分析2003～2007年间经手术病理证实的4例RO的CT资料，全部经MSCT多期检查，包括平扫、增强皮质期、髓质期和排泄期扫描。结果4例RO均为单发病灶，左右各2例，呈膨胀性生长，边界清，最大径线在2．0～6．5cm，平均4．4cm，中位数3．5cm。2例三期增强扫描出现典型的辐辏样强化、中央星芒样瘢痕和包膜，得以正确诊断。1例对中央瘢痕延迟强化的认识不足，术前误诊为肾细胞癌。1例轻度强化，未见包膜，术前误诊为肾细胞癌。所有病灶内未见钙化和出血。结论RO的CT典型征象是在三期增强扫描出现辐辏样或均匀强化、中央星芒样瘢痕和包膜，中央瘢痕可以出现延迟强化，但肿瘤强化不明显时，和肾细胞癌鉴别诊断困难。

CT imaging features of renal oncocytoma

Objective To study the imaging features of renal oncocytoma （RO） and to improve the diagnostic accuracy. Methods CT imaging features in 4 patients with RO confirmed by surgery pathology from 2003 to 2007 were reviewed retrospectively. All patients underwent MSCT including pre-contrast as well as post-contrast（cortico- medullary phase, parenchymal phase and excretory phase） scanning. Results Four cases had 4 RO lesions and half in right kidney. All of them manifested as expansion growth type and the maximum dimension of them ranged from 2.0-6.5cm with the average 4.4cm and the median 3.5cm. Two lesions were diagnosed correctly for all characteristics of RO showed on all phases of post-contrast scanning, such as convergence shape enhancement, central stellate scar and psudocapsule. Two lesions were misdiagnosed as renal cell carcinoma because of one with delay enhancement of central stellate scar and the other with homogenously little enhancement. There was no calcification and hemorrhage in all lesions. Conclusion Most ROs show certain CT imaging characteristics, including convergence shape or homogenous enhancement, central stellate scar and psudocapsule on post-contrast images. The central stellate scar can enhanced delay. When the mass has little enhancement, it is difficult to differential diagnosis with renal cell carcinoma.