Ariel I, Abeliovich D, Bar-ziv J, Hochberg A
Department of Pathology, Hadassah Medical Center, Jerusalem, Israel.
Pediatr Pathol Lab Med. 1996 Nov-Dec;16(6):1013-21. doi: 10.1080/15513819609168725.
The Wilms' tumor-aniridia-genital anomalies-mental retardation (WAGR) syndrome is associated with an increased risk for developing Wilms' tumor. A right nephrectomy was performed following the diagnosis of Wilms' tumor in a 2-year-old girl with WAGR syndrome and chromosome 11, del 11p13. Pathologic examination revealed intralobar nephrogenic rests and a peripelvic multicystic mass, sharply delineated from the adjacent typical intralobar nephrogenic rests and renal parenchyma, which may represent a cystic Wilms' tumor (cystic partially differentiated nephroblastoma). We studied the expression of the H19 gene by in-situ hybridization performed on paraffin sections of the kidney. H19 is an imprinted maternally-expressed gene that is not translated to protein and functions as a regulatory RNA molecule. It is tightly linked with the paternally-imprinted gene of insulin-like growth factor 2. While IGF2 presumably plays a role in tumorigenesis of Wilms' tumor, H19 is not expressed in the majority of Wilms' tumors. The expression of H19 in the intralobar nephrogenic rests was found to be prominent in the component of the blastema and markedly reduced with differentiation to tubular structures similar to the fetal kidney. The differential diagnosis of hyperplastic intralobar nephrogenic rests from a small Wilms' tumor arising in intralobar nephrogenic rests is difficult. Complete understanding of the chain of molecular events occurring in the evolution of Wilms' tumors may lead to the development of tumor markers to be used on paraffin sections and so help in the differential diagnosis of hyperplasia versus malignant transformation.
威尔姆斯瘤-无虹膜-泌尿生殖系统畸形-智力发育迟缓（WAGR）综合征与发生威尔姆斯瘤的风险增加相关。一名患有WAGR综合征且染色体11存在11p13缺失的2岁女孩在被诊断出威尔姆斯瘤后接受了右肾切除术。病理检查显示叶内肾源性残留和肾盂周围多囊性肿块，与相邻的典型叶内肾源性残留和肾实质界限清晰，这可能代表囊性威尔姆斯瘤（囊性部分分化型肾母细胞瘤）。我们通过对肾脏石蜡切片进行原位杂交研究了H19基因的表达。H19是一个印记的母源表达基因，不翻译成蛋白质，作为一种调节性RNA分子发挥作用。它与父源印记的胰岛素样生长因子2基因紧密连锁。虽然IGF2可能在威尔姆斯瘤的肿瘤发生中起作用，但大多数威尔姆斯瘤中不表达H19。发现H19在叶内肾源性残留的胚基成分中表达突出，随着向类似于胎儿肾脏的管状结构分化而明显减少。区分叶内肾源性残留的增生性病变与叶内肾源性残留中发生的小威尔姆斯瘤很困难。全面了解威尔姆斯瘤演变过程中发生的分子事件链可能会导致开发可用于石蜡切片的肿瘤标志物，从而有助于增生与恶性转化的鉴别诊断。
