Imaging of a supernumerary kidney

Abstract

A 33-year-old female patient was investigated for a right lower quadrant pain. The investigation, which included an excretory urography and a computed tomography examination, revealed a normal kidney on the right side and another two normal sized, complete kidneys on the left side, which appeared to have a small parenchymal bridge. The patient was treated surgically for a cyst of the right ovary.

Unusual drainage of the main kidney on accessory kidney

“…The standard treatment for an accessory kidney is simple nephrectomy if the patient is symptomatic or has complications, or the kidney has a negligible function. [2,4,6] In our case, nephrectomy was contraindicated because the drainage of the main kidney was supported by the accessory kidney. Surgeons must be aware of this variety of developmental anomaly before conducting irreversible surgery, and this awareness depends on reliable imaging.…”

“…The collecting system of the accessory kidney may drain directly into the bladder, or rarely, to the vagina, or may coalesce with the ureter of the main kidney. [4] Even though it is a congenital abnormality, patients may remain asymptomatic until adolescence. [1] The average age at diagnosis is 36 years, and because 1/3 of the cases remain asymptomatic, they are often diagnosed incidentally.…”

“…[1] The average age at diagnosis is 36 years, and because 1/3 of the cases remain asymptomatic, they are often diagnosed incidentally. [4] The usual symptoms include fever, pain and a palpable abdominal mass. [1,2,5,6] Hydronephrosis, stones, pyonephrosis, pyelonephritis and malignant changes may accompany the accessory kidney.…”

“…[1,5] It can also be associated with congenital anomalies, such as the coarctation of aorta, horseshoe kidney, double collecting system, vaginal atresia and ectopic ureter. [4,7,8] In this case, the patient was admitted with complaints of pain, ureteral Although no proven mechanisms exist for the embryological development of the accessory kidney, a number of hypotheses have been proposed. The parenchyma of the accessory kidney may develop as an outcome of the division of either one nephrogenic blastema or two separately blooming nephrogenic blastema.…”

“…The ureters to these embryonic organs stem from the Wolffian duct and develop by a premature division of either a single ureteric bud or two separately developed buds, resulting in partial or complete duplication anomalies. [1][2][3][4] Accessory kidneys can be diagnosed by EU, US, retrograde urography, nuclear imaging, CT and MRI scans. [2,5,6] The diagnosis may be complicated by the smaller size or reduced function of the accessory kidney and its superimposition on the normal kidney.…”