Primitive Neuroectodermal Tumors (PNETs) are tumors that primarily affect the soft tissue. It was first believed that these specific tumors came from stem cells although there is now evidence that shows they may also come from specialized cells as well. PNETs are a specific type of medulloblastoma, a highly malignant tumor of the brain. Medulloblastomas are the most common type of malignant brain tumor that occurs in children, representing about thirty percent of all cases. These types of tumors occur in only one percent of the adult population. Most of these tumors appear in the midline of the brain, although they are quite often found in the lateral portion of the cerebellum as well. PNETs often appear in children under the age of fifteen. There are also slightly higher rates in Caucasians and males as compared to African-American and females.
Unfortunately there are no pathognomonic signs or symptoms related to PNETs. Most symptoms are specific to the area where the tumor manifests or are caused by excess pressure on the brain. Some symptoms include irritability, loss of energy, vomiting, headaches, and vision, hearing, and balance changes. Some children, specifically under the age of two, also have an increased head circumference. Depending on the size and location of the tumor, most people will not die from a PNET. Although it is not often seen, it is possible that sudden death could occur due to obstructions caused by hydrocephaly (water on the brain).


All information used in this blog was obtained through the following websites:
http://www.thedoctorsdoctor.com/diseases/pnet.htm
http://emedicine.medscape.com/article/1157440-overview