Learn all about juvenile pilocytic astrocytoma its symptoms, prognosis and treatment options. Pilocytic Astrocytoma (also called Juvenile Pilocytic Astrocytoma. Juvenile pilocytic astrocytomas are tumors that form from astrocytes, star-shaped cells that maintain brain and spinal cord health.
Pilocytic astrocytomas comprise approximately 5-6% of all gliomas. This tumour type has an overall incidence of 0.37 per 100,000 persons per year. Pilocytic astrocytomas are typically seen in children and young adults. They can occur at all ages in children and teens, but the median age for a juvenile pilocytic astrocytoma (JPA) is 5 to 14 years. This tumour type is unusual in infants and very rare in adults. These grade I astrocytomas typically stay in the area where they started and do not spread. They are considered the “most benign” (noncancerous) of all the astrocytomas.
Symptoms commonly associated with increased pressure on the brain include headaches, lethargy or drowsiness, vomiting, and changes in personality or mental status. In some cases, a JPA may also be associated with seizures, vision problems such as blurred vision or double vision (diplopia), gradual changes in behavior or mood, and weakness of the arms and legs resulting in coordination difficulties.
Approximately 13,000 Americans die of malignant brain tumors every year, representing about 2% of all U.S. cancer deaths. Approximately 55% of these deaths are men. The single most important factor related to incidence of and survival from malignant brain tumors is age: the prognosis is more favorable in the under-40 age group.
Each year, 8.2 of every 100,000 people in the U.S. are diagnosed with primary malignant brain tumors. They represent approximately 2% of all cancers diagnosed in the United States. Currently, 29.5 of every 100,000 people in the U.S. have primary malignant brain tumors (just diagnosed or under treatment).
Pilocytic and Anaplastic Astrocytoma
Pilocytic astrocytomas (i.e., WHO grade I) arise throughout the neuraxis, but preferred sites include the optic nerve, optic chiasm/hypothalamus, thalamus and basal ganglia, cerebral hemispheres, cerebellum, and brain stem. These tumors show low cellularity, low proliferative and mitotic activity, and rarely metastasize or undergo malignant transformation. Findings on cytogenetic analysis are typically normal, although gains of chromosomes 7 and 8 are observed in one third of tumors. Mutational inactivation of the TP53 gene does not appear to play a role in the evolution of this tumor. Anaplastic astrocytoma (i.e., WHO grade III) arises in the same locations as diffuse astrocytomas, with a preference for the cerebral hemispheres. These tumors show increased cellularity, distinct nuclear atypia, marked mitotic activity, and a tendency to infiltrate through neighboring tissue. A high frequency of TP53 and PTEN mutations has been recognized in adult tumors, with pediatric tumors showing much less. Anaplastic Astrocytomas tend to have tentacle-like projections that grow into surrounding tissue, making them difficult to completely remove during surgery.
What is Juvenile Pilocytic Astrocytoma?
Juvenile pilocytic astrocytoma (JPA) is a rare childhood brain tumor. In most cases, the tumor is a benign, slow growing tumor that usually does not spread to surrounding brain tissue A JPA develops from certain star-shaped brain cells called astrocytes. Astrocytes and similar cells form tissue that surrounds and protects other nerve cells found within the brain and spinal cord. Collectively, these cells are known as glial cells and the tissue they form is known as glial tissue. Tumors that arise from glial tissue, including astrocytomas, are collectively referred to as gliomas.
Juvenile Pilocytic Astrocytoma Symptoms
The symptoms associated with juvenile pilocytic astrocytomas vary depending upon the size and location of the tumor. Symptoms may differ among patients and often depend on the location and size of the tumor. The most common symptom is increased intracranial pressure.
- puberty or diencephalic Nausea,
- An impaired ability to coordinate voluntary movements (ataxia),
- Wryneck (torticollis)
- Ocular symptoms including swelling of the optic disc (papilledema) and involuntary rapid eye movements (nystagmus) may also occur. In some cases, paralysis (palsy) of the sixth and seventh cranial nerves may develop.
- Vision loss and degeneration (atrophy) of the optic nerve. Papilledema and protrusion of the eyeball (proptosis).
- A JPA in the hypothalamic region may be associated with weight gain or loss, premature syndrome, which is characterized by failure to thrive, abnormal thinness, irritability, and eye abnormalities.
Juvenile Pilocytic Astrocytoma Prognosis
A prognosis is an estimate of the likely progress of a disease after a diagnosis, based on an average patient group. In low-grade astrocytomas, complete surgical resection is associated with 5-year survival rates as high as 95-100% without further treatment. Patients with subtotal resections may have only a 60-80% survival rate over similar periods; however, after partial resection, long-term progression-free intervals may ensue. Current operative mortality rates are less than 1%. Morbidity depends largely on tumor location and is highest in diencephalic tumors, in which the incidence of hemiparesis or visual field deficits may be 10-20%.
Treatment of Juvenile Pilocytic Astrocytoma
Treatment of juvenile pilocytic astrocytomas (JPAs) is not required at all, if they are not causing symptoms, then ongoing observation and regular MRI scans may be all that’s needed to make sure the tumor is not growing. If the juvenile pilocytic astrocytoma is causing symptoms, or if a scan shows the tumor to be changing or growing, the pediatric neurosurgeon may recommend taking action. Treatment options include:
Surgery, if the tumor is located in an area that can be reached surgically, the best choice is usually to remove it. Total resection, or removal, usually provides a complete cure
Radiation therapy is sometimes recommended as a follow-up to surgery if the neurosurgeon wasn’t able to remove the entire tumor. Since radiation can have long-term effects on development, it’s not usually recommended for young children.
Chemotherapy is included in some treatment plans to stop the growth and spread of cancer cells and also to allow for smaller radiation doses. Chemotherapy can be given in pill form or as an IV drip. The chemotherapy goes on for several months and usually does not require hospitalization.