Bilateral pelvic kidneys with PUJ obstruction, fusion and right-sided duplex system

Case contributed by Muhammad Shoyab


Recurrent pain in right iliac fossa for many years. Recurrent urinary tract infections (UTI). Appendectomy done for the RIF pain 30 years ago.

Patient Data

Age: 70 years
Gender: Male

Both kidneys are identified in lower abdomen — right kidney in right iliac fossa, and left kidney superomedial to it, extending over the midline, sitting in between right & left common iliac arteries. 
Both kidneys are fused at their facing surface anterior to the distal part of the right common iliac artery just proximal to its bifurcation.

Long axis of the left kidney is parallel to the vertebral column, with its hilum directed anteriorly and leftwards.

Long axis of the right kidney is parallel to the right psoas major muscle, with its hilum directed anteriorly. A complete cortical band is noted across its mid-polar region, producing two separate collecting systems. Upper moiety pelvis is mildly widened, and unites with the more prominent extrarenal lower moiety pelvis to form a common pelvis. The pelvis has thickened walls with moderate enhancement, as well as internal septations and abrupt narrowing at the pelviureteric junction (PUJ). However, there is no perirenal fat stranding, fluid collection or lymphadenopathy.

Both kidneys excrete contrast promptly and symmetrically.
No dilatation, narrowing or filling defect is seen in either ureter.


Crossed-fused ectopic kidneys located near right iliac fossa
Partial duplex collecting systems in right kidney
Pyelitis and PUJ obstruction/stenosis on right side
Mild pelviectasis on left side, due to PUJ obstruction/stenosis
Prompt & symmetric uptake & excretion of contrast by both kidneys

Case Discussion

This case is interesting in that it contains multiple developmental anomalies of the renal system in the same patient, along with their sequelae.

Considering the unresolved RIF pain even after appendectomy, it may be understood that the appendicitis was only secondary to the adjacent pyelitis.

The pyelitis and PUJ obstruction are perhaps secondary to the abnormal configuration, crossing vessels and recurrent UTI. The PUJ obstruction may also be primary/congenital, but probably that would have, by this age, progressed to more significant obstructive uropathy and deteriorated renal function.

This case also adds evidence to the concept that renal developmental anomalies may not produce symptoms continually, but may have fluctuating complaints, alternating with phases having complaints or insignificant imaging findings. 1 To determine whether a particular anomaly is associate with a patient's symptoms, it may be necessary to conduct imaging during the acute phase of symptoms. 1

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