The answer to this question depends on the type of brain tumor, as well as the location of the tumor itself. Generally speaking, the most difficult brain tumor to remove is one that is located deep in the brain, or one that is large and infiltrates surrounding tissue.
Glioblastoma multiforme (GBM) is considered the most aggressive and difficult to treat type of brain tumor. It is also one of the most common and is usually located in the deeper parts of the brain. GBM tumors are usually composed of a mix of different cell types and can be difficult to surgically remove due to their infiltrative nature. Additionally, they tend to grow quickly and can be hard to control with radiation or chemotherapy.
Another type of tumor that can be difficult to remove is a meningioma. These tumors originate in the membranes surrounding the brain and spinal cord and can be difficult to remove due to their location. They can also be large and infiltrative, making surgical removal more difficult.
In addition to tumor type and location, other factors can make brain tumors more difficult to remove. For instance, tumors that are near important structures in the brain such as blood vessels, nerves, or the brain stem can be more complex and difficult to remove without damaging surrounding tissue. Additionally, the age and overall health of the patient can influence the success of a surgery.
No matter the type or location of a brain tumor, it is important to consult with a neurosurgeon for a thorough evaluation and treatment plan.