Angiomatous meningioma: Case report of a rare tumor and a brief review of the literature

Angiomatous meningioma (AM), a rare World Health Organization (WHO) Grade I subtype of meningioma, which presents special diagnostic and therapeutic challenges. Our patient is a 56-year-old male with a history of cranial radiation therapy 15 years ago, who was presenting with progressive neurological symptoms, including severe headaches, generalized tonic-clonic seizures, personality change, and left homonymous hemianopia. The imaging studies revealed a large (5.2 x 4.8 x 4.1cm) heterogeneously enhancing, highly vascular mass in the right parieto-occipital area with severe peritumoral edema and mass effect. The complexity of the diagnosis was due to the high vascularity and dural location, as well as the patient's history
The multidisciplinary tumor board discussion recommended surgical resection. During surgery, the tumor was markedly vascular (more than 60% of mass volume) and required extreme attention to hemostasis when performing a Simpson Grade II resection. Pathology showed a WHO Grade I AM with numerous local vascular spaces, meningothelial cells, hyalinized perivascular sclerosis, and atrophic nuclear atypia. EMA, CD31, CD34, progesterone receptor, and SSTR2A were positive; EMA and Ki-67 were low, and molecular analysis revealed monosomy 22. Even after re-exploration due to postoperative hemorrhage, the patient had full neurological recovery. Postoperative seizure risk continued to be controlled at four-year follow-up. This case highlights the diagnostic complexity and rarity of AMs, especially in patients with prior radiation treatment, and demonstrates how good prognoses can be achieved with extensive, specialized treatment despite initial complications.