Rare aetiology of obstructive kidney injury: Bilateral ureteral endometriosis

Endometriosis is highly prevalent in women at the reproductive age, ranging from 6-10%, though ureteral involvement is rare, only seen in 0.1% of the cases, but may lead to urinary tract obstruction with potential renal function loss. As endometriosis has a non-specific symptomology, diagnosis may be elusive, though it must be considered in order to prevent irreversible kidney injury and resultant morbidity. Here we present a 29-year-old Caucasian female with a past medical history of infertility and dysmenorrhoea who presented with a stage II acute kidney injury. On initial diagnostic approach, moderate bilateral ureterohydronephrosis was detected by ultrasound, assuming extrinsic compression, but no specific cause was recognizable. In order to diagnose the obstruction’s aetiology, Magnetic Resonance Imaging was used. This did not reveal an objective cause. Given the circumstances, workup ended in an explorative laparotomy, revealing a “frozen pelvis” due to endometriosis, confirmed histologically. Due to difficult ressecability, a conservative approach was taken through hormonal treatment and bilateral ureteral pigtail placement, given the necessity to salvage renal function and decrease disease burden.