Retroaortic retrocaval reverse horseshoe kidney associated with vertebral and spinal cord anomalies.

While horseshoe kidneys are the most common renal fusion anomaly, various complex variant anatomies exist. One rare form is the retroaortic retrocaval reverse horseshoe kidney, where the upper poles fuse posterior to both the aorta and inferior vena cava. These intricate renal anomalies increase complication risk and complicate surgical interventions. We report a 3-year-old boy diagnosed with a retroaortic retrocaval reverse horseshoe kidney during a spinal deformity evaluation. This case is one of few instances of this specific variant documented in the literature and is the first to be associated with type 1 diastematomyelia and tethered cord.