Pancake kidney

Last revised by Mostafa El-Feky on 30 Jan 2023

Pancake kidney (also known as discoid kidneydisc kidney, lump kidney, fused pelvic kidney or cake kidney) is a rare renal fusion anomaly of the kidneys of the crossed fused variety.

Pancake kidney may be an incidental finding. However, they can present clinically because of conditions that affect normal kidneys, such as:

The upper and lower poles of the kidneys are fused hence giving it an appearance of pancake 5 and usually give rise to two separate ureters which enter the bladder in a normal relationship. 

An even more rare variant is when the cake kidney is drained by a single ureter (has been previously reported in only four patients) 5.

Pancake kidneys usually are situated anterior to the aortic bifurcation.

Pancake kidney can be demonstrated on ultrasound, CT, IVU, MRI, and scintigraphy.

Pancake kidney malformation is not necessarily associated with renal dysfunction but does require exclusion of concomitant anomalies and long-term follow-up for early detection of possible future complications such as:

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Cases and figures

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  • Case 1
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  • Case 2
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  • Case 3
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  • Case 4
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