Arroyo M R, Green D M, Perlman E J, Beckwith J B, Argani P
Department of Pathology, The Johns Hopkins Hospital, Baltimore, Maryland 21231-2410, USA.
Am J Surg Pathol. 2001 Apr;25(4):433-44. doi: 10.1097/00000478-200104000-00002.
The authors report nine new metanephric adenofibroma (MAFs; previously termed nephrogenic adenofibroma) and 16 related tumors from the files of the National Wilms Tumor Study Group Pathology Center (NWTSGPC). All tumors contained a variable amount of a bland spindle cell stroma, which is essentially identical to the recently described metanephric stromal tumor (MST). Features that distinguish this stroma from congenital mesoblastic nephroma (CMN) include intratumoral angiodysplasia, concentric cuffing of entrapped tubules ("onion skinning"), and heterologous differentiation. The epithelial components of these lesions spanned a wide range of appearances. All tumors contained at least focally an inactive embryonal epithelium identical morphologically to metanephric adenoma (MA), and hence each case could be classified as containing MAF. The epithelium of nine tumors had this appearance throughout, and hence these were considered usual MAFs. The epithelium of four tumors demonstrated increased mitotic activity but was otherwise similar to MA. The epithelial component of seven tumors spanned a morphologic spectrum from inactive MA to malignant epithelial predominant Wilms tumor (WT), with gradual transitions noted in several cases. Five other tumors contained a carcinomatous component distinct from these lesions but identical morphologically to papillary renal cell carcinoma (PRCC). In one of these cases, this component had metastasized to the regional lymph nodes at the time of diagnosis. No tumor recurred during follow-up, although almost all patients received adjuvant therapy for WT regardless of their tumor's histology and NWTSGPC diagnosis. In conclusion, MAF is a biphasic tumor that spans the morphologic spectrum between benign pure stromal (MST) and pure epithelial (MA) lesions, and can merge with the morphology of WT, supporting the concept that these are all related lesions. A relationship to PRCC is also evident.
作者从国家肾母细胞瘤研究组病理中心（NWTSGPC）的档案中报告了9例新的后肾腺纤维瘤（MAF；以前称为肾源性腺纤维瘤）及16例相关肿瘤。所有肿瘤均含有数量不等的形态温和的梭形细胞间质，这与最近描述的后肾间质肿瘤（MST）基本相同。该间质与先天性中胚层肾瘤（CMN）的区别特征包括肿瘤内血管发育异常、被包绕小管的同心袖套样改变（“洋葱皮样”改变）以及异源性分化。这些病变的上皮成分表现多样。所有肿瘤至少局灶性含有形态上与后肾腺瘤（MA）相同的静止胚胎上皮，因此每例均可归类为含有MAF。9例肿瘤的上皮在整个肿瘤中均为此种表现，因此这些被认为是普通MAF。4例肿瘤的上皮有丝分裂活性增加，但其他方面与MA相似。7例肿瘤的上皮成分在形态上从静止的MA到以恶性上皮为主的肾母细胞瘤（WT）呈谱系变化，在几例中可见逐渐移行。另外5例肿瘤含有与这些病变不同但形态上与乳头状肾细胞癌（PRCC）相同的癌性成分。在其中1例中，该成分在诊断时已转移至区域淋巴结。尽管几乎所有患者无论其肿瘤组织学类型及NWTSGPC诊断如何均接受了WT辅助治疗，但随访期间无肿瘤复发。总之，MAF是一种双相性肿瘤，其形态谱系介于良性纯间质（MST）和纯上皮（MA）病变之间，并可与WT的形态相融合，支持了这些均为相关病变的概念。与PRCC的关系也很明显。
