Intracranial arteriovenous malformation (AVM) or meningothelial meningioma (MM)? Outlining the similarities and differences on imaging studies for an accurate diagnosis, case report

INTRODUCTION AND IMPORTANCE: AVM and MM represent neurosurgical challenges, not only when involving eloquent brain, but also by posing a significant intraoperative haemorrhagic risk. It is a challenge in itself to establish a proper differential diagnosis between the two lesions, especially since they require distinct interventional plan of action. We present the case of a patient initially diagnosed by specialists with an intracranial AVM, which was revealed intraoperatively to be in fact an MM. CASE PRESENTATION: A 29-years patient, transferred to our department by urgency. The patient symptoms started two weeks prior admission with severe headache and vomiting. A cerebral computer tomographic angiography (CTA) was performed and interpreted by radiologists, as a large left frontal AVM. CLINICAL DISCUSSION: Upon through review the majority of surgical team believed the mass to be AVM. However, during surgery it turned out to be Meningioma. The patient underwent a left pterional craniotomy with removal of the tumour, classified as Simpson grade II. The pathological exam confirmed the lesion to be an MM. CONCLUSIONS: Acquiring neuro-radiological expertise is vital for the neurosurgeon, as well as fast ability for adjusting the initial action plan with the intraoperative discoveries. An experienced eye can benefit the patient by obtain a correct diagnosis in most difficult cases.