Review Question - QID 109062

A 6-year-old boy presents to your office with loss of his peripheral vision. His mother discovered this because he was almost struck by a vehicle that "he couldn't see at all". In addition, he has been complaining of a headache for the last several weeks and had an episode of vomiting 2 days ago. He has a family history of migraines in his mother and grandmother. He is currently in the 80th percentile for height and weight. On physical exam his temperature is 99°F (37.2°C), blood pressure is 110/75 mmHg, pulse is 100/min, respirations are 19/min, and pulse oximetry is 99% on room air. He is uncooperative for the rest of the physical exam. During workup, a lesion is found in this patient. Which of the following would most likely be seen during histopathologic analysis?