Spontaneous arterial rupture complicating neurofibromatosis type 1: a case report of massive lumbogluteal hematoma and literature review.

Neurofibromatosis type 1 (NF1) is a multisystem genetic disorder in which vascular dysplasia can lead to rare, life-threatening spontaneous hemorrhage. We present the case of a 62-year-old male NF1 patient who presented with acute left lumbar pain and swelling without a history of trauma or anticoagulant use. Computed tomography (CT) revealed a large hematoma in the left lumbogluteal region and a presacral mass. Active bleeding from the left second lumbar artery and the subcostal artery was confirmed by digital subtraction angiography and successfully managed with transcatheter arterial embolization (TAE). The postoperative course was complicated by hematoma rupture and secondary infection. This was controlled with ultrasound-guided drainage (yielding approximately 3000 mL of old blood), debridement, and targeted antibiotic therapy (clindamycin). This case illustrates the rare yet complete clinical trajectory of spontaneous arterial rupture in NF1, from massive hematoma formation to infectious complications. It underscores that acute pain or an unexplained mass in an NF1 patient should raise immediate suspicion for spontaneous hemorrhage, necessitating prompt vascular imaging and multidisciplinary intervention to improve outcomes.