Nondilated obstructive uropathy (obstructive nephropathy without hydronephrosis) can be a challenge to diagnose.
Typical obstructive nephropathy:
(1) hydroureter
(2) hydronephrosis
(3) oliguria
Features of nondilated obstructive uropathy:
(1) absence of hydroureter and hydronephrosis
(2) elevated serum creatinine
(3) dramatic improvement with stent placement
Possible causes:
(1) retroperitoneal fibrosis
(2) retroperitoneal malignancy (primary or metastatic)
(3) acute obstruction prior to dilatation
