肾脏少见原发性恶性肿瘤的CT表现

CT findings of rare primary malignant renal tumors

目的:探讨肾脏少见原发性恶性肿瘤的CT表现特点。方法:对经病理证实的9例肾脏少见原发性恶性肿瘤的CT表现进行回顾性分析,并结合文献分析肾脏少见原发性恶性肿瘤的CT表现特点。结果:类癌1例,平扫肿瘤呈不均匀等低密度,边界不清,瘤体大部突出于肾外,增强扫描肿瘤呈轻中度不均匀强化,病灶内部可见线条状强化血管影穿行。成人肾母细胞瘤2例,CT平扫肿瘤与周缘组织分界较清,见假包膜,瘤内见低密度囊变坏死区及斑片状稍高密度出血影,增强扫描病灶实质部分明显强化,肿瘤周缘见少量不规则强化血管影。恶性纤维组织细胞瘤2例,CT平扫肿瘤边界不清,瘤内见片状密度减低区,增强扫描肿瘤明显强化。平滑肌肉瘤4例,CT平扫肿瘤呈等低混杂密度,边界模糊,瘤内见片状密度减低区;增强扫描肿瘤呈轻-中度强化,其中2例表现为延迟强化。结论:肾脏少见原发性恶性肿瘤术前极易误诊,结合临床资料、发病率及影像表现可以提高诊断准确率,确诊仍需依靠病理检查。

Objective：To discuss the CT characteristics of rare primary malignant renal tumor. Methods：CT findings of 9 cases with pathology proved rare primary malignant renal tumor were retrospectively analyzed and literatures were reviewed. Results：Carcinoid （1 case）. Tumor showed heterogeneous hypo-/iso- attenuation on plain CT scan, ill-defined, mainly protruded outwards from the renal contour. Mild to moderate inhomogeneous enhancement after contrast administration, intra-tumoral linear enhanced vascular opacities could be assessed. Adult Wilms tumor （2 cases）. On plain CT, tumor had clear boundary and pseudocapsule,intra-tumoral low density cystic necrotic areas and patchy slightly high density hemorrhagic components could be assessed. After contrast administration, there were markedly enhanced solid component and irregularly enhanced blood vessels at the periphery of tumor. Malignant fibrous histiocytoma （2 cases）. The boundary of tumor was ill-defined on plain CT, with intra-tumoral patchy low attenuated area, marked enhancement of tumor could be re vealed after contrast administration. Leiomyosarcoma （4 cases）. On plain CT, tumors showed mixed iso-/low attenuation with blurred boundary and intra-tumoral patchy low attenuated areas. Mild to moderate enhancement was showed and 2 cases showed delayed enhancement. Conclusion：Rare primary malignant renal tumor was very often misdiagnosed before surgery. Improvement of diagnostic accuracy could be obtained as clinical data, incidence in combination with imaging findings, yet the final diagnosis is still relied on pathology.