Nervous system tumor

Primary tumors can affect either the peripheral nervous system (PNS) or the central nervous system (CNS). They may be either benign or malignant. A nerve sheath tumor may be found in both the CNS and PNS. There are over 120 types of brain and spinal cord tumor. Some common types include: • Gliomas: Tumors arising from glial cells, which support and protect neurons. Subtypes are astrocytomas (from astrocytes), oligodendrogliomas (from oligodendrocytes), and glioblastomas (thought to derive from astrocytes). • Medulloblastomas: Malignant tumors that commonly occur in the cerebellum, most often in children. They only extremely rarely become malignant. • Neurofibromas: Benign tumors that grow on nerves, commonly associated with neurofibromatosis type I (NF1). Secondary tumors Secondary tumors in the CNS, or metastatic tumors, occur when cancer cells spread to the brain or spinal cord from a primary tumor in another part of the body. These tumors are more common than primary CNS tumors in adults and often originate from cancers of the lung, breast, skin, kidney, or colon. == Diagnosis ==

Diagnosis typically begins with a comprehensive medical history, and a neurological examination. The goal of the evaluation is to identify any neurological changes that may suggest the presence of a tumor. The assessment considers factors such as the nature, progression, and duration of the presented symptoms. Nervous system tumors can have a wide range of presentations, and a clinical evaluation is often followed by neuroimaging to confirm or rule out the presence of a tumor. Further testing, such as a biopsy, may be necessary to determine the tumor type and grade. Additional imaging techniques can provide further insights. Histopathological examination determines the tumor type, grade, and molecular characteristics, which are critical for guiding treatment decisions. In some cases, a liquid biopsy by way of a lumbar puncture (spinal tap) may be performed to analyze cerebrospinal fluid (CSF). This can help detect tumor cells, especially in cases of suspected brain tumor metastasis, or primary CNS lymphoma. The presence of tumor markers or abnormal cells in the CSF can provide diagnostic information that complements imaging and biopsy findings. == Epidemiology ==

Nervous system neoplasms vary in incidence and type based on factors such as age, tumor origin, and malignancy. Overall, brain and spinal tumors are more common in females due to the higher prevalence of meningiomas. They are the most common brain tumor in children up to 14 years (25.7%), the next most commonly found are pilocytic astrocytomas (17.5%), and embryonal tumors (15.7%). The overall incidence rate of brain tumors in children is 6.2 per 100,000. Glioblastomas are the most aggressive malignant glioma and make up approximately 47.7% of all gliomas, and are more commonly found in males. Their incidence rate is 3.23 per 100,000 people. The 5-year survival rate for glioblastoma is only 6.8%. Meningiomas, which develop in the meninges, are common brain tumors, representing approximately 37% of all brain tumors. The incidence rate for meningiomas is 9.51 per 100,000 people. Unlike gliomas, more than 98% of meningiomas are benign. The 5-year survival rate for nonmalignant meningiomas is approximately 91%. The distribution and behavior of nervous system neoplasms differ significantly between adults and children. Gliomas are more frequent and aggressive in adults, while certain benign tumors like pilocytic astrocytomas are more common in children. Notably, adults are more likely to develop secondary (metastatic) tumors that spread to the nervous system from cancers originating in other parts of the body. ==See also==