黏液样小管状及梭形细胞肾癌的CT诊断

CT diagnosis of mucinous tubular and spindle cell renal carcinoma

目的：探讨黏液样小管状及梭形细胞肾癌（MTSRCC）的CT表现,提高对该病的认识。方法：回顾性分析8例经手术病理证实的MTSRCC的CT表现,8例均行MSCT平扫及三期增强扫描。分析病灶大小、位置、形态、平扫密度、强化方式和程度、有无周边侵犯、淋巴结和远处转移等征象。结果：8例MTSRCC均为单发病灶,CT上表现为边界清晰的类圆形或椭圆形肿块,最大直径平均为4.53cm（1.8~7.6cm）,平扫7例呈等或稍高密度,1例呈低密度,1例伴同侧肾结石,均未见出血和钙化。增强扫描肿瘤呈渐进性轻度强化,6例呈均匀强化,2例呈不均匀强化,其强化程度明显低于正常肾脏皮质,8例皮髓质期和延迟期平均CT值分别增加26.2HU和33.6HU,肿瘤与肾皮质的强化比值皮髓质期和延迟期分别为21.54%和33.28%。结论：MTSRCC为好发于成年女性的较罕见低度恶性肿瘤,在CT上表现为边界清晰、出血坏死及钙化少见的规则肿块,可伴有同侧肾结石,具有平扫以等密度为主,渐进性轻度强化的特点。

Objective：To discuss the CT manifestations of mucinous tubular and spindle cell renal carcinoma（MTSRCC）and to improve the understanding of this tumor.Methods：The CT features of 8patients with surgery and pathology proven MTSRCC were retrospectively analyzed.Non-enhanced and triphasic enhanced CT scanning were performed in all of the 8patients.The size,location,density in plain CT and the enhanced pattern and degree of the tumor,as well as the adjacent involvement,retroperitoneal lymph node and distant metastasis were analyzed.Results：All of the 8patients with MTSRCC presented as single,well-defined,oval or round mass with the mean maximum diameter as 4.53cm（1.8~7.6cm）.Iso-attenuation or slightly hyper-attenuation of the tumor was revealed on plain CT in 7cases,and hypo-attenuation in 1case.Association with nephrolithiasis in 1case.No intra-tumoral hemorrhage or calcification was identified.Tumor showed as gradually mild enhancement after contrast administration,homogeneous enhancement was showed in 6patients and heterogeneous enhancement in 2patients.The enhancement degree was apparently less than that of normal renal cortex.The mean CT value of the tumor in these 8patients increased at cortico-medullary phase and delayed phase was 26.2HU and 33.6HU respectively.The ratio of tumor and renal cortex in cortico-medullary phase and delayed phase was 21.54%and 33.28%respectively.Conclusion：MTSRCC is a rarely seen renal neoplasm with low degree malignancy,which predominantly presents in adult women.The CT features include well-defined,mass,necrosis and calcification are seldom,could be associated with nephrolithiasis,iso-attenuated on plain CT and with progressively mild enhancement.