This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
In a survey, many children are examined and were found to have urogenital abnormalities. Which congenital anomaly is associated with increased risk of bladder carcinoma? 
Select and explain. 
A. Medullary sponge kidney, B. Bladder extrophy, C. Unilateral renal agenesis, D. Double ureter
B: Bladder extrophy
Answer: B: Bladder extrophy 
Explanation: Ectopia vesicae(extrophy of the bladder)is incomplete development of the infraunbilical pa of the anterior abdominal wall and anterior bladder wall.Umbilicus is absent & there is separation of pubic bones.In males,epispadias is commonly present with rudimentary prostate & seminal vesicle In females,defective external genitalia is common.Problems associated with bladder extrophy are repeated soakage,ulceration,pain,recurrent pyelonephritis,renal failure,Metaplastic changes in mucosa can lead into adenocarcinoma of bladder. Reference:SRB's manual of surgery,5th edition,page no:1029