Pseudotumoral Presentation of a Cervical Extracranial Vertebral Artery Aneurysm in Neurofibromatosis Type 1

OBJECTIVE: Neurofibromatosis Type 1 (NF1) is known to be associated with vascular lesions. Association with an extracranial vertebral artery aneurysm is very rare. We report the case of such an aneurysm mimicking a cervical neurofibroma in NF1. CLINICAL PRESENTATION: An 18-year-old woman with previously diagnosed NF1 presented with a C6 radiculopathy. There were no clinical features suggesting a vascular origin for the lesion. The computed tomographic and standard magnetic resonance imaging scans showed a C5-C6 contrast-enhancing lesion responsible for bony erosion. Subsequent, magnetic resonance angiography and digital subtraction angiography diagnosed the lesion as a C5-C6 vertebral artery aneurysm. INTERVENTION: The lesion was treated by endovascular occlusion of both the aneurysm and the parent vertebral artery with an initial immediate disappearance of the pain. CONCLUSION: This case serves as a reminder of the importance of ruling out a vertebral artery aneurysm with angiography when managing cervical lesions in patients with NF1.