Introduction: Although haemangioblastomas are the most common primary intra-axial infratentorial tumors in adults, they are nontheless rare in general. They are benign, low-grade capillary haemangiomas, that can be sporadic or associated with Von Hippel-Lindau syndrome.

Aims: We present a case with acute subarachnoid hemorrhage resulting from a hemangioblastoma. This case highlights the importance of the differential diagnosis of subarachnoid haemorrhage.

Discussion: A 29-year-old woman was admitted to the emergency room after a sudden loss of consciousness. A CT+CTA was performed, which showed extensive subarachnoid haemorrhage (SAH), most prominent in the posterior fossa, and what appeared to be a left vertebral artery aneurysm. She was immediately referred to neurointervention. The initial scans could not be shared with the interventional team due to technical reasons. The patient was transported to our clinic, a control head CT and CTA was performed, which confirmed the extensive SAH, but instead of an aneurysm, the report described a large cystic tumor at the level of the cranio-cervical junction, containing signs of acute bleeding. Digital substraction angiography (DSA) showed dissection in both vertebral arteries, floating thrombus in both vessels, and a large cystic hypervascularised tumour that was supplied diffusely by both vertebral arteries, that could not be properly characterised based on DSA findings. Thrombectomy was performed in both vertebral arteries and the patient recieved a drain into the left lateral ventricle. Follow-up CT showed progression of the haemorrhage and diffuse cerebral edema. She recieved another ventricular drain as rescue therapy, and was then immediately taken to the operation room for haematoma evacuation and tumour resection. The day after surgery, the patient died of complications of paralytic ileus and sepsis. Pathology confirmed the tumor to be a haemangioblastoma with signs of extensive haemorrhage.

Conclusion: Haemangioblastomas can uncommonly present with subarachnoid haemorrhage. This possibility shoud be cosidered in case of a posterior fossa predominant subarachnoid haemorrhage and a strongly enhancing aneurysm-like nodule at an atypical location on CTA. This can ensure appropriate immediate medical intervention with improved patient outcomes.

Funding: The authors have no conflicts of interest to declare.