A brain tumor is an abnormal growth of cells in brain or skull that can be malignant or benign (benign).
Brain tumors are neoplasms resulting from abnormal and uncontrolled growth of brain cells (neurons, glial cells, epithelial cells, myelin-producing cells, etc.). (primary brain tumor) or originates in another part of body and spreads to brain (secondary brain tumor or metastatic brain tumor). Brain tumors usually occur in posterior third of brain during childhood and in anterior two-thirds of brain in adulthood.primary brain tumor
Primary brain tumors are named after type of cells they come from. Common histological types are glioma, glioblastoma, astrocytoma, oligodendroglioma, medulloblastoma, meningioma, and glioma. Tumors may be benign and are usually, but not necessarily, limited to a small area. They can also be malignant and invasive (i.e. spread to neighboring areas). Brain cells can be damaged by tumor cells: (i) direct compression of brain cells by tumor growth, (ii) indirect effects of inflammation in and around tumor, (iii) cerebral edema (swelling), or (iv) increased pressure in skull ( due to cerebral edema or impaired CSF circulation).metastases to brain
Secondary or metastatic brain tumors occur in tumor cells that spread from another part of body to brain. They are more common than primary brain tumors. About a quarter of metastatic cancers spread to brain. The lungs and mammary glands are most common sources of secondary brain tumors. Tumor cells enter brain through blood vessels. Because brain does not have a lymphatic drainage system like other organs (the cerebrospinal fluid system acts like lymphatic system in brain), it is unlikely that cranial nerves can spread tumor cells via lymphatic route (which is very common in cancers). in other organs). Unlike primary brain tumors, metastatic tumors can occur in various distant locations in brain. Highly aggressive brain tumors such as glioblastoma can also be seen in a few locations, but usually in advanced stages of disease.Symptoms and complications of a brain tumor
Local tissue damage (by direct or indirect mechanism) causes focal neurological symptoms that vary depending on location of brain tumor. Hemiplegia, aphasia, difficulty speaking, ataxia, hemihypesthesia (numbness and decreased sensation on one side of body), and local headaches are some of symptoms caused by local effects of a brain tumor. Increased pressure on skull or swelling of brain can lead to broader symptoms such as generalized headaches, nausea and vomiting, loss of consciousness (coma or coma), and mental decline. Seizures are also often observed due to local irritant effects of brain tumors or metabolic changes caused by cancer. Infants with brain tumors may have an enlarged head circumference, raised mastoid processes, or suture separation due to incomplete development of skull during infancy.
Neurological examination reveals local (specific to location of tumor) or systemic neurological changes. Slowly progressive neurological symptoms suggest a possible brain tumor, and diagnosis is confirmed by CT or MRI of head. In difficult cases, angiography, EEG, or brain biopsy may help. While slow progression is an important feature of disease, some brain tumors can grow rapidly, causing sudden neurological changes. Treatment consists of surgery to remove tumor mass or kill tumor cells with radiation therapy (radiotherapy) and/or drugs (chemotherapy).
Primary or secondary brain tumors can lead to brain herniation (displacement of part of brain tissue due to mass effect of lesion, usually resulting in compression of neurons that control respiratory system of brainstem, which ultimately leads to death) and permanent sexual neurological changes, including mental decline.Treatment of a brain tumor
Treatment takes into account whether tumor is a primary brain tumor or a metastatic brain tumor. Metastatic disease requires treatment of original tumor, if applicable. Some primary brain tumors respond better to certain treatments than others.
The main treatments for brain tumors include: