Neuro Oncology: Brain and Spinal Tumors

These tumors originate in the brain itself and are classified based on the type of cells involved or the location within the brain.

Gliomas:

• Astrocytomas: Arise from astrocytes, a type of glial cell. They can range from low-grade (slow-growing) to high-grade (fast-growing) tumors like glioblastomas.
• Glioblastoma Multiforme (GBM): The most aggressive type of astrocytoma, classified as grade IV. It is highly malignant and difficult to treat.
• Oligodendrogliomas: Develop from oligodendrocytes, another type of glial cell. These tumors tend to be slower growing.
• Ependymomas: Arise from ependymal cells, which line the ventricles of the brain and the central canal of the spinal cord. They can occur at any age but are more common in children.

Meningiomas:

These tumors arise from the meninges, the protective layers surrounding the brain and spinal cord. Most meningiomas are benign, though they can cause significant symptoms by pressing on the brain or spinal cord.

Medulloblastomas:

A type of primitive neuroectodermal tumor (PNET), medulloblastomas are malignant tumors that arise in the cerebellum, the part of the brain that controls balance and coordination. They are most common in children.

Pituitary Tumors:

These tumors arise from the pituitary gland, a small gland at the base of the brain that regulates hormones. Most pituitary tumors are benign adenomas, but they can cause a variety of hormonal imbalances.

Schwannomas:

Also known as acoustic neuromas, these tumors arise from Schwann cells, which produce the myelin sheath that insulates nerves. They typically develop on the nerve that controls hearing and balance.

Craniopharyngiomas:

These benign tumors develop near the pituitary gland and the base of the brain, often affecting hormonal functions and vision.

Pineal Region Tumors:

These tumors occur in or around the pineal gland, a small gland located near the center of the brain. They can be either benign or malignant.

Metastatic Brain Tumors: These tumors originate from cancers located elsewhere in the body and spread (metastasize) to the brain. Common primary cancers that spread to the brain include lung, breast, melanoma, kidney, and colon cancers.

Chordomas:

• Rare, slow-growing tumors that develop from remnants of the notochord, a structure present in early embryonic development. They usually occur at the base of the skull or the lower spine.

Hemangioblastomas:

• Benign tumors that arise from blood vessels in the brain or spinal cord. They are often associated with von Hippel-Lindau disease, a genetic disorder.

Germ Cell Tumors:

• These tumors arise from germ cells, which are cells that give rise to sperm and eggs. They can occur in the brain, typically near the pineal gland or pituitary gland.

Dysembryoplastic Neuroepithelial Tumors (DNETs):

• Rare, benign tumors that usually occur in children and young adults, often causing seizures.

Central Neurocytomas:

• Rare, typically benign tumors that arise in the ventricles of the brain, often affecting young adults.
  

Intramedullary Tumors

These tumors originate within the spinal cord itself.

• Astrocytomas: The most common type of intramedullary tumor, usually benign but can be malignant.
  
• Ependymomas: Also common intramedullary tumors, often benign, but they can sometimes spread within the central nervous system.
  
• Hemangioblastomas: Benign tumors that are often associated with von Hippel-Lindau disease.

Intradural-Extramedullary Tumors

These tumors occur within the spinal canal but outside the spinal cord.

• Meningiomas: Arise from the meninges, the protective layers surrounding the spinal cord. They are usually benign.
  
• Schwannomas and Neurofibromas: Tumors that develop from the nerve roots extending from the spinal cord. Schwannomas are generally benign, and neurofibromas are associated with neurofibromatosis.
  
• Myxopapillary Ependymomas: A subtype of ependymoma found in the filum terminale, the lower part of the spinal cord.

Extradural Tumors

These tumors occur outside the dura mater, the outermost membrane covering the spinal cord, often involving the vertebral bones.

• Vertebral Tumors: Tumors that arise from the bones of the spine. They can be benign (like osteoid osteomas) or malignant (like osteosarcomas).
  
• Metastatic Tumors: Cancers that have spread from other parts of the body to the spine. Common primary sites include the lungs, breasts, prostate, and kidneys.
  
• Chordomas: Rare, slow-growing tumors that typically occur at the sacrum or the base of the skull. They originate from remnants of the notochord.
  

Primary Spinal Tumors

These tumors originate in the spine or spinal cord.

• Gliomas: Including astrocytomas and ependymomas, which arise from glial cells within the spinal cord.
  
• Meningiomas: Arising from the meninges surrounding the spinal cord.
  
• Schwannomas and Neurofibromas: Arising from nerve roots.
  
• Hemangioblastomas: Blood vessel tumors often associated with genetic conditions.

Secondary (Metastatic) Spinal Tumors

These tumors originate from cancers elsewhere in the body and spread to the spine. They are often located in the vertebral bodies.

Common Primary Sites:

• Lung Cancer
  
• Breast Cancer
  
• Prostate Cancer
  
• Kidney Cancer
  
• Thyroid Cancer
  

Plasmacytomas:

• Tumors made up of abnormal plasma cells, often associated with multiple myeloma. They can develop in the spine and cause spinal compression.

Lymphomas:

• These are cancers of the lymphatic system that can involve the spinal cord or vertebral column. Primary central nervous system lymphomas can affect the spine.

Giant Cell Tumors:

• Rare, generally benign tumors that can occur in the bones of the spine. They have a tendency to recur after treatment and can occasionally become malignant.
  

Osteoid Osteomas and Osteoblastomas:

Benign bone tumors that can occur in the spine. Osteoid osteomas are usually small and painful, while osteoblastomas are larger and may require surgical removal.