Rare giant renal artery aneurysm in neurofibromatosis type 1 patient: a case report.

Introduction and importance: Neurofibromatosis type 1 (NF1) is a genetic disorder characterised by multiple neurofibromas, café-au-lait spots, and iris hamartomas. The variety of vasculopathies that can occur in NF1 make it difficult for clinicians to accurately follow-up patients. Most cases of vasculopathies are stenotic, and, in few cases, aneurysms may form. Case presentation: A 35-year-old male presented with extreme left flank pain for the past 2 days. His physical examination revealed whole-body several café-au-lait skin macules, a subcutaneous lesion, and a palpable abdominal mass in the left flank. His laboratory workup was within normal ranges. A multi-slice computed tomography and computed tomography angiogram with contrast outlined a giant left renal artery aneurysm (RAA). A kidney salvage surgery was planned. However, due to ectatic dilatation and large extension of the aneurysm, the affected renal artery branches and renal vein were found unfit for auto-transplantation during the surgical procedure and a total nephrectomy was necessary. Symptoms improved significantly postoperatively and no complications developed. Clinical discussion: RAA is an uncommon finding in NF1 patients. Diagnosis is often dependent on computed tomography angiogram. Management techniques are conservative, endovascular, or surgical. In few surgical cases, a total nephrectomy may be necessary if auto-transplantation is not feasible. Conclusion: Despite its rarity, the diagnosis of RAA should be considered in patients with NF1 presenting with flank pain. Moreover, early screening for renal vasculopathies can evade critical surgical outcomes including a total nephrectomy. Hence, the authors recommend a total vascular workup for these patients, consisting of doppler ultrasound and, if necessary, a multi-slice computed tomography with contrast.