Horseshoe kidney

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Overview
Horseshoe kidney (also known as renal fusion) is a congenital disorder, affecting about 1 in 400 people, in which a person's two kidneys fuse together to form a horseshoe-shape during development in the womb.

Pathogenesis
The central portion of the kidney ends up inferior to the inferior mesenteric artery, since its embryological ascent is arrested by its presence. This is the most common type of fusion anomaly in the kidneys.

Symptoms
Persons affected by this disease may experience nausea, abdominal discomfort, kidney stones and urinary tract infections.

Diagnostic Findings
Patient #1: CT images demonstrate a horseshoe kidney

Images courtesy of RadsWiki

Associated conditions
The presence of horseshoe kidneys in females with Turner Syndrome is about 15%.

Treatment
There is not an existing cure for renal fusion.

Complications

 * Ureteropelvic junction obstruction (UPJ)
 * Recurrent infections occur because of urine stasis and associated vesicoureteral reflux.
 * Nephrolithiasis related to UPJ obstruction or infection may occur.
 * An increased risk of trauma to the isthmus exists because of its position anterior to the spine.
 * Some evidence suggests an increased incidence of certain renal tumors in horseshoe kidney.