Final answer:
Glioblastoma is the #1 most common intracranial tumor in adults, while meningioma is the #2 most common. Glioblastoma is an aggressive brain tumor, while meningioma is usually benign.
Step-by-step explanation:
The #1 most common intracranial tumor in adults is glioblastoma, which is a type of brain tumor that starts in the brain or spinal cord tissue. Glioblastoma is an aggressive cancer that can spread quickly and is often difficult to treat. It can cause symptoms such as headaches, seizures, and changes in mood or behavior.
The #2 most common intracranial tumor in adults is meningioma, which is a tumor that forms in the membranes that surround the brain and spinal cord. Meningiomas are usually benign, meaning they are not cancerous, but they can still cause symptoms depending on their size and location.