Right lump kidney with varied vasculature and urinary system revealed by multidetector computed tomographic (MDCT) angiography.

Renal ectopia also known as ectopic kidney is an embryological renal anomaly characterised by abnormal anatomical location of one or both of the kidneys. This can occur in various forms such as (1) crossed fused renal ectopia, (2) ectopic thoracic kidney and (3) pelvic kidneys. The lump kidney is one of the six variations of crossed fused ectopic kidney. Throughout life, the patient may remain asymptomatic, however, symptomatic patients may present with minor traumatic injuries due to the abnormal location or normal kidney pathologies. During normal embryological development, there is cephalic migration during which the kidneys ascend to their normal retroperitoneal location; therefore, an ectopic location is as a result of arrested migration. During this embryological development the kidney has multiple aorto-illiac branches, which degenerate when the kidney reaches its normal location. Here they develop new renal branches from the aorta and during an arrested ascent the ectopic kidney tends to retain some of the older aorto-iliac vessels. Hence, the arterial supply and the veineux drainage are grossly abnormal, reflecting the metanephric malascent and the primitive vascular arrangement. The collecting systems also present with important anatomical variations. We present an extremely rare case of right lump kidney with six renal arteries, two renal veins and two duplicated pelvicalyceal systems.