Cobra head appearance is described for ?

Ureterocoele shows cobra head or adder head appearance in Excretory urography . Ureterocele is cystic enlargement of intramural ureter thought to result from congenital atresia of ureteric orifice. Female : Male is 4:1 . Similar to ectopic ureter , ureterocele frequently drain the upper pole and are associated with nonfunctional kidney . Present with infection in children and stones in adults . IVU is infrequently done now , Cystoscopy is diagnostic :-Translucent cyst enlarging and collapsing as urine flows in from upper ureter. Treatment in uncomplicated cases is exision and reimplantation. Endoscopy diathermy incision for symptomatic ureterocoele. Advanced U/L cases with hydronephrosis or pyonephrosis , NEPHRECTOMY.( Bailey 27th , chap 76 , pg no 1401