[Latent ureteric outlet stenosis in young adults - the diagnostic significance of functional assessment in cases of marked hydronephrosis].

Congenital ureteropelvic junction (UPJ) obstruction may remain clinically compensated until young adulthood despite prenatal or early childhood diagnosis. Distinguishing morphological hydronephrosis from functionally significant obstruction is crucial for therapeutic decision-making. Case: A 25-year-old woman was found to have mild right-sided pelvicalyceal dilatation as an incidental finding during a routine primary care evaluation. Several weeks later, following a urinary tract infection accompanied by flank pain, repeat imaging demonstrated marked progression of hydronephrosis. Further evaluation with computed tomography and Tc-99m-MAG3 renography revealed a urodynamically significant right-sided urinary outflow obstruction despite preserved split renal function. Owing to the documented progression, functional obstruction, and persistent urinary stasis, robot-assisted pyeloplasty was performed. Postoperatively, urinary drainage improved while renal function remained stable.

Conclusion

In adults with hydronephrosis, therapeutic decisions should not be based solely on the degree of morphological dilatation. Clinical evolution and functional assessment of urinary drainage are essential for appropriate management.