Crossed fused renal ectopia

Case contributed by Ammar Ashraf


Asymptomatic baby with history of ectopic right kidney.

Patient Data

Age: 2 years
Gender: Male

Tc-99m DMSA

Nuclear medicine

Normally located left kidney at its expected anatomical position. No radiotracer uptake in the right renal fossa with right kidney seen across the midline along the inferior pole of the left kidney (crossed fused renal ectopia). Both kidneys show homogeneous radiotracer distribution. No renal cortical scars are seen. Differential renal function; upper left renal moiety=54% and lower right renal moiety=46%.


Empty right renal fossa. Both kidneys are visualized on the left side of the abdomen and are fused with each other; upper moiety representing the left kidney measures 6.4 x 3.5 cm and the lower moiety representing the right kidney measures 4.6 x 2.5 cm.

Case Discussion

Scan findings are suggestive of left-sided crossed fused renal ectopia with the upper moiety representing left kidney and lower moiety representing the crossed fused ectopic right kidney. Both renal moieties are well functioning without any evidence of cortical scars.

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