This is a group of tumors that develop from the primitive nerve cells left over from the gestational development of the child’s nervous system. Normally, these cells can be harmless although in some cases it can become cancerous. These are the malignant (cancerous) tumors of the central nervous system that has the potential to spread easily through the cerebrospinal fluid and in some cases, it can also spread beyond the central nervous system. PNET stands for a group of tumors because of their appearance that looks similar when examined under the microscope. Some of the different types of PNET include medulloblastoma, pineoblastoma and central nervous system PNET. The medulloblastoma develops in the cerebellum of the brain, pineoblastoma occurs in the middle of the brain near the pituitary gland and the central nervous system PNET develops in the forebrain. Medulloblastoma is considered to be the second most common brain tumor that affects children that have the potential to grow quickly and spread to other parts of the brain and the spinal cord. Peripheral PNETs can also develop outside the central nervous system such as the bone, pelvis and the chest wall.
Symptoms
The symptoms of PNET are based on the location of the tumor. Medulloblastomas often causes a condition called hydrocephalus where the normal flow of cerebrospinal fluid can become disrupted causing pressure within the skull. This can cause symptoms such as weakness or change in sensation on a single side of the body, irritability, nausea and vomiting, morning headache, seizures, unexplained weight loss or weight gain, change in energy level and change in personality. In the case the condition is advanced, it can present dizziness, double vision, problems with walking and loss of coordination. Symptoms of PNET of the spine include back or leg pain, weakness in the legs and impaired bowel or bladder function.
Diagnosis
The diagnosis begins with a physical examination, history of the individual and with various tests. An MRI imaging and computer tomography (CT) scan will be done to determine the size and the characteristic feature of the tumor. During the imaging procedure, an agent will be administered intravenously that can present contrast image of the tumor against the normal brain. In the case a tumor of the brain is identified, a biopsy will be required that will remove a sample of the affected tissue to be examined under the microscope to detect the characteristic finding.
Treatment
The treatment is normally based on the age of the child, their health, the location of the tumor, its size and if the cancer has spread to other parts of the central nervous system. Surgery is the main treatment option to remove the tumor as much as possible. During the surgery, the fluid accumulation can also be relieved by making a hole to drain the fluid to another part of the brain or by placing a tube called the shut in place. Chemotherapy may also be used after a surgery to stop the tumor from returning.
References
http://www.columbianeurosurgery.org/conditions/primitive-neuroectodermal-tumors/
