Schenk J P, Schrader C, Furtwängler R, Ko H S, Leuschner I, Graf N, Troeger J
Abt. Päd. Radiologie Universitätsklinik Heidelberg, Im Neuenheimer Feld 153, 69120 Heidelberg.
Rofo. 2005 Oct;177(10):1373-9. doi: 10.1055/s-2005-858359.
To differentiate classic and cellular type of congenital mesoblastic nephroma (CMN) in MRI and to evaluate MRI for staging according to the Societe Internationale de Oncologie Pediatrique (SIOP).
MRI examinations of 20 children with CMN (age 1st to 16th months, classic type n = 11, cellular type n = 7, mixed type n = 2) were analyzed retrospectively. Cysts, necrosis, hemmorhage in the tumor, signal intensity, tumor structure, thrombosis and dilatation of renal vein, crossing of the body midline, peripheral contrast-enhancement, tumor volume and existence of a tumor pseudocapsule in contrast to the residual kidney were described. The radiologic stage was compared with the histopathologic stage (infiltration of perirenal fat and infiltration of the renal sinus).
Tumors of the classic type (mean volume 67.9 ml) had necrosis in 1 case, crossed the midline in 1 case, had no cysts or bleeding, and had a peripheral contrast-enhancement in 1 case, and were heterogeneous in 9 cases. The cellular type (mean volume 302.8 ml) had tumor necrosis in 6 cases, bleeding in 3 cases, cysts in 3 cases, crossed the midline in 4 cases, and peripheral contrast enhancement in 2 cases, and was predominantly heterogeneous. Mixed tumor types (7 ml and 202 ml) had tumor necrosis in 1 case and crossed the midline in 1 case, a peripheral contrast enhancement in 2 cases and a homogenous structure in 1 case. The signal intensity in T1 w and T2 w images was not specific. The renal vein was inconspicuous in all children. The evaluation of the infiltration in perirenal fatty tissue was true positive in 1 case, true negative in 10 cases, false negative in 4 cases and false positive in 5 cases. The infiltration of the renal hilus was true positive in 10 children, false positive in 8 cases and true negative in 2 cases.
A typical finding of CMN in MRI is a heterogeneous tumor without demarcation from the rest of the kidney parenchyma by a pseudocapsule. The cellular type of CMN tends to have a higher tumor volume and shows more necrosis, bleeding and cysts than the classic type in MRI. A peripheral contrast-enhancement in MRI is not characteristic for any type of CMN. Local tumor staging is not possible with MRI.
在磁共振成像（MRI）中鉴别先天性中胚层肾瘤（CMN）的经典型和细胞型，并根据国际小儿肿瘤学会（SIOP）标准评估MRI对CMN的分期。
回顾性分析20例CMN患儿（年龄1至16个月，经典型n = 11，细胞型n = 7，混合型n = 2）的MRI检查结果。描述肿瘤内的囊肿、坏死、出血、信号强度、肿瘤结构、肾静脉血栓形成及扩张、是否越过身体中线、周边强化情况、肿瘤体积以及与残余肾相比有无肿瘤假包膜。将放射学分期与组织病理学分期（肾周脂肪浸润和肾窦浸润）进行比较。
经典型肿瘤（平均体积67.9 ml）1例有坏死，1例越过中线，无囊肿或出血，1例有周边强化，9例呈不均匀性。细胞型肿瘤（平均体积302.8 ml）6例有肿瘤坏死，3例有出血，3例有囊肿，4例越过中线，2例有周边强化，主要呈不均匀性。混合型肿瘤（7 ml和202 ml）l例有肿瘤坏死，1例越过中线，2例有周边强化，1例结构均匀。T1加权和T2加权图像上的信号强度无特异性。所有患儿肾静脉均不明显。肾周脂肪组织浸润评估真阳性1例，真阴性10例，假阴性4例，假阳性5例。肾门浸润真阳性10例，假阳性8例，真阴性2例。
CMN在MRI上的典型表现是肿瘤不均匀，无假包膜与肾实质其余部分分界。CMN细胞型在MRI上往往肿瘤体积更大，坏死、出血和囊肿比经典型更多。MRI上的周边强化对任何类型的CMN均无特征性。MRI无法进行局部肿瘤分期。
