Abstract
We recently encountered two female pediatric cases of paraurethral cyst associated with ipsilateral renal agenesis. Paraurethral cyst is a rare lesion and its etiology remains obscure. Therefore, we attempted to investigate the pathogenesis from a viewpoint of renal development at the beginning of metanephric period. The metanephrogegesis is organized by the ureteric bud developing from the mesonephric duct. Then, failure to form a ureteric bud may cause not only ipsilateral renal agenesis but persistent mesonephric duct: the mesonephric duct presists in the wall of the urogenital sinus, a part of urethral primordium. In this fashion it is suggested that the persistent mesonephic duct has a chance to grow into a paraurethral cyst. The high frequency of simultaneus occurrence of paraurethral cyst and renal agenesis may support this theory which has been also proposed by Mackie and Stephens in 1975. In this paper diagnosis and treatment of this lesion were also described.
