This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disease of Infancy & Childhood, Subject name: Pathology
Which histological finding in resected kidney indicated Bilateral Wilm's tumor? 
Select and explain. 
A. Blastemal component, B. Nephrogenic rests, C. Skeletal muscle differentiation, D. Abnormal mitotic figures
B: Nephrogenic rests
Answer: B: Nephrogenic rests 
Explanation: Ans. (b) Nephrogenic rests(Ref: Robbins 9th/pg 479- 481)Nephrogenic restsThey are putative precursor lesions of Wilms tumorsPatients with presence of nephrogenic rests in the resected specimen, are at an increased risk of developing Wilms tumors in the contralateral kidney and require frequent and regular surveillance.