Malignant tumors of the central nervous system, or CNS -- meaning the brain and spinal cord -- are relatively rare compared to other cancers, but when they do occur, they are often deadly. The Central Brain Tumor Registry of the United States reports that from 2002 to 2006, over 85,000 cases of malignant CNS tumors were reported. Seventy-five percent of these resulted in mortality within that time period. MedlinePlus notes that gliomas and meningiomas are the most common brain tumors. Rare effects of brain cancer include such tumor varieties as ependymomas, primary lymphomas, pineal gland tumors and primary germ cell tumors.
Ependymoma
This type of tumor grows in the CNS, most commonly at the bottom of the brain near its juncture with the spinal cord. It can travel through the cerebrospinal fluid, a protective and nourishing liquid that bathes the spinal cord, and it affects different areas of the nervous system. Symptoms of ependymoma include dizziness, difficulty balancing, headache and gastrointestinal distress, according to the Department of Neurosurgery at UCLA.
Primary Lymphoma
This cancer of the lymphatic system can cause death within two months if left untreated. Lymphoma can occur throughout the body, but when the lymph nodes of the brain are involved, this cancer causes symptoms ranging from speech and vision changes, to seizures, confusion and hallucinations. Chemotherapy may lengthen survival by several years.
Pineal Gland Tumor
The Virginia Commonwealth University's Massey Cancer Center notes that tumors of the pineal region of the brain may be of several different types, and surgical biopsy is often performed to determine whether the tumor is malignant or benign. Though extremely rare, various types of tumors such as blastomas, gliomas and benign cysts have been known to occur in the vicinity of the pineal gland. Tumors in this region can cause headaches and increased pressure within the skull.
Germ Cell Tumor
The National Cancer Institute reveals that germ cell tumors typically arise in the central region of the brain, close to the pineal gland, and they may be either benign or malignant. When malignant, these tumors can metastasize, or spread, throughout the brain and spinal cord. This type of tumor is most common in children and in those who have Klinefelter syndrome, a genetic disorder wherein a male possesses an extra X chromosome. Germ cell tumors may cause headaches, lethargy, enlarged head size, visual impairment and hormonal irregularities.
