Negre T, Faure A, Andre M, Daniel L, Coulange C, Lechevallier E
Service d'urologie et de transplantation rénale, CHU de la Conception, 147, boulevard Baille, 13385 Marseille, France.
Prog Urol. 2011 Nov;21(12):837-41. doi: 10.1016/j.purol.2011.06.006. Epub 2011 Jul 19.
Angiomyolipoma is the most frequent benign renal solid tumor. Because of the lack of fat component on the CT scan, diagnosis of this tumor is hard and can require percutaneous biopsy of unknown renal tumor. The follow-up of the poor fat CT scan component AML (PFCT AML) is uncertain.
Five hundred percutaneous renal biopsy under tomodenstitometry have been realised between 1998 and 2008. There was 41 PFCT AML on the 500 biopsy. By definition, a PFCT AML is an AML where the diagnosis is done on a percutaneous biopsy but where there was no fat component on the first CT scan. We studied and compared clinical, tomodensitometric and histologic parameters of these 41 patients (mean age: 56, 9±11.04; sexe rate M/F: 6/35) where renal AML was diagnosed on percutaneous renal biopsy but without fat component on CT scan. Average size was 26.44±14.68mm. We phone-called 16 patients for the long-term follow-up. Average follow-up was 41±28.3 months. For four patients on 16, initial diagnosis was done in front of local symptoms, for one of the 16 diagnosis was done in front of general symptoms, for one of the diagnosis was done during Bourneville tuberous sclerosis evolution and 10 of the 16 was done fortuitously.
After review of the initial CT scan, fat density was found on 24% of them. Ten percent was epithelioid angiomyolipoma. Four renal biopsy on 41 (10%) was epithelioid AML. No epithelioid AML had fat component after the second look of the CT scan. Among the 16 patients who were phone-called, three (19%) underwent a complication. Two had abdominal pain and was treated medically. Initial sizes were 26 and 30mm. Only one patient must be operated by radical nephrectomy for acute hemorrhage. Initial size was 45mm. No neoplasic degeneration was identified for those 16 patients.
In our study, the PFCT AML rate was 8.2%. In 25% cases, CT scan read-through shown a fat component and could help for the diagnosis. PFCT AML evolution seems to be the same as a classic AML. Conservative treatment had a good covering because there was no death and no malignant evolution. However, we found 10% of epithelioid angiomyolipoma in which malignant risk is high. PFCT AML diagnosed on renal percutaneous biopsy of unknown renal tumor requires the same management than the classic AML.
血管平滑肌脂肪瘤是最常见的肾脏良性实性肿瘤。由于CT扫描上缺乏脂肪成分，该肿瘤的诊断困难，可能需要对不明肾脏肿瘤进行经皮活检。脂肪成分少的CT扫描表现的血管平滑肌脂肪瘤（PFCT AML）的随访情况尚不确定。
1998年至2008年间共进行了500例在体层摄影术引导下的经皮肾活检。500例活检中有41例PFCT AML。根据定义，PFCT AML是指经皮活检确诊为AML，但首次CT扫描时无脂肪成分的情况。我们研究并比较了这41例患者（平均年龄：56.9±11.04岁；男女比例为6/35）的临床、体层摄影和组织学参数，这些患者经皮肾活检诊断为肾AML，但CT扫描无脂肪成分。平均大小为26.44±14.68mm。我们给16例患者打电话进行长期随访。平均随访时间为41±28.3个月。16例中有4例因局部症状进行了初始诊断，16例中有1例因全身症状进行了诊断，16例中有1例在结节性硬化症演变过程中进行了诊断，16例中有10例是偶然发现的。
复查初始CT扫描后，24%发现有脂肪密度。10%为上皮样血管平滑肌脂肪瘤。41例中有4例肾活检（10%）为上皮样AML。再次查看CT扫描后，没有上皮样AML有脂肪成分。在打电话随访的16例患者中，3例（19%）出现了并发症。2例有腹痛，接受了药物治疗。初始大小分别为26mm和30mm。只有1例患者因急性出血必须行根治性肾切除术。初始大小为45mm。这16例患者未发现肿瘤变性。
在我们的研究中，PFCT AML的发生率为8.2%。25%的病例中，CT扫描复查显示有脂肪成分，有助于诊断。PFCT AML的演变似乎与经典AML相同。保守治疗效果良好，因为没有死亡病例，也没有恶性演变。然而，我们发现10%的上皮样血管平滑肌脂肪瘤恶性风险较高。经皮肾活检诊断为不明肾脏肿瘤的PFCT AML与经典AML需要相同的处理。
