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Horseshoe kidney

Case contributed by Dr Abdel-Rahman Abdel-Halim


Pelvic ultrasound revealed ovarian cyst for further CT evaluation.

Patient Data

Age: 30
Gender: Female

Both renal lower poles are seen pointing medially and seen fused across the midline by an isthmus of functioning renal tissue.

The ureters arise from the kidneys anterior rather than medially. Both have average caliber and normal distal insertion.

No stones or back pressure changes are seen.

A right sided adnexal cyst is seen. It measures about 7.5x6 cm in its maximum axial diameter. It showed thin imperceptible wall with no solid components or calcific foci seen.

Case Discussion

Horseshoe kidney is one of the most common renal fusion anomalies, found in approximately 1 in 400-500 adults. It exists when the lower poles of the kidney are fused together during development as a fetus. 

Most of the time, a horseshoe kidney is an incidental find on an exam for some other condition that the patient is having. In this case the patient had a pelvic pain and US revealed a large ovarian cyst and the gynecologist requested CT for abdomen and pelvis.

CT is probably the study of choice as it can show the complications that may associate the anomaly e.g. renal calculi and obstructive uropathy.

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