Pancake kidney

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

Clinical presentation

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

Gross anatomy

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 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 bifurcation of the abdominal aorta.

Radiographic features

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

Treatment and prognosis

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

Differential diagnosis


Abdominal and pelvic anatomy
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Article Information

rID: 25480
System: Urogenital
Section: Anatomy
Synonyms or Alternate Spellings:
  • Fused pelvic kidney
  • Cake kidney
  • Discoid kidney
  • Disc kidney
  • Pancake kidneys
  • Disc kidneys
  • Doughnut kidneys
  • Discoid kidneys
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    Figure 1: illustration
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    Both ureters inse...
    Case 1
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