Renal duplication and contralateral pelvic ectopic kidney in an adult: a case report

Introduction and importance: Congenital anomalies of the kidney and urinary tract are common, but the coexistence of two distinct anomalies in the same patient has been rarely reported. The contralateral association of a pelvic ectopic kidney and a duplicated collecting system also has practical consequences for any future pelvic, vascular, or endourological procedure. Case presentation: A 42-year-old woman with no notable medical history presented with intermittent pelvic pain of about 3 months’ duration, without urinary symptoms or fever. Physical examination revealed tenderness of the right iliac fossa and hypogastrium, with no palpable mass. Serum creatinine was 0.8 mg/dL (71 µmol/L), giving an estimated glomerular filtration rate of 94 mL/min/1.73 m 2 (CKD-EPI 2021); urinalysis was normal. Abdominopelvic ultrasound, followed by contrast-enhanced computed tomography (CT) with multiplanar and three-dimensional reconstructions, demonstrated a right kidney in an ectopic pelvic (iliac) position and a left kidney with incomplete pyelocalyceal duplication, showing a parenchymal bridge and malrotation of the lower moiety, without hydronephrosis, stones, or infection. Clinical discussion: This malformative association is most often asymptomatic and discovered incidentally. A pelvic kidney may be mistaken for an adnexal mass or another retrovesical tumor; its reniform shape, sinus fat, enhancement, and excretion on CT identify it. As both anomalies are usually silent, the association is probably under-recognized; its interest lies in what the anatomy implies for future procedures. Conclusion: In the absence of complications and with preserved renal function, conservative management with surveillance is appropriate. Recognizing and documenting this anatomy matters more than its rarity.