A Potentially Fatal Cause of Sciatica: A Rare Case of Nerve Compression Caused by a Pseudoaneurysm of the Renal Artery of a Transplanted Kidney.

Renal transplant is the gold standard treatment for end-stage kidney disease (ESKD). Despite the evolution of renal transplant procedures, complications can still occur. Transplant renal artery pseudoaneurysm is a rare but potentially life-threatening complication, which can be asymptomatic or cause mass-effect symptoms. We report an unusual case of a pseudoaneurysm of an unfunctional renal transplant that caused a femoral nerve compression, mimicking lumbosacral radiculopathy. The case concerns a 38-year-old woman with primary focal segmental glomerulosclerosis (FSGS) that progressed to ESKD. The patient underwent a kidney transplant that failed a few years after the surgery. More than 10 years later, she presented with symptoms consistent with lumbosacral radiculopathy, which was ultimately diagnosed as femoral nerve compression caused by a transplant renal artery pseudoaneurysm. This case emphasizes that each patient's medical history should always be considered when assessing even common complaints because rare causes can manifest in frequent symptoms. On the other hand, this case makes us reflect on weighing up the cost/benefit of some diagnostic investigations, as it is important not only to investigate the most common causes but also to rule out, in selected patients, those that, although rare, can be life-threatening.