Benign Astrocytoma
Benign Astrocytoma Definition
Benign astrocytoma (or astrocytoma Grade I, astrocytoma Grade II, intracranial neoplasm, intracranial tumor) is categorized into two types: Diffuse (Adults, cerebral hermisphere and brainstem) and circumscribed (Children, characteristic location/morphology). They are benign tumors that occur in the brain or spinal cord. Symptoms and severity of the astrocytoma depends on its location and size.
Benign Astrocytoma Diagnosis
A CT or MRI scan is necessary to characterize the anatomy of this tumor and determine its size, location, and consistency. The CT scan will usually show distortion of third and lateral ventricles with displacement of anterior and middle cerebral arteries. Histologic diagnosis combined with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing capacity of the tumor. It may be cavitating, pseudocyst-forming, or noncavitating. Its appearance is usually white-gray, firm, and almost indistinguishable from normal white matter.
Benign Astrocytoma Symptoms and Signs
Patients with benign astrocytoma usually experience headaches, mental changes, increased irritability, and emotional instability. They may also undergo reduced mental activity and may have increased forgetfulness and confusion. There may also be a loss of initiative, loss of spontaneity, and an impaired ability to control voluntary movements. The patient may also undergo symptoms such as lethargy, stupor, nausea, vomiting, slowed heartbeat, incontinence, and paralysis. Astereognosis and aphasia may also be involved. Some patients present themselves with complaints of facial pain and facial numbness, coupled with rapid involuntary eye movements. In almost half of the cases, the first symptom of an astrocytoma, whether benign or malignant, is the onset of seizure, either focal or generalized. Between 60 to 75% of patients will experience recurrent seizures in the course of their illness. Headache and signs of increased intracranial pressure (resulting to headache and vomiting) usually present late in the disease course. In younger patients, the tumor is usually located in the cerebellum and will present with some combination of vision deterioration (uncorrectable by glasses), instability in walking, unilateral ataxia, and signs of increased intracranial pressure (resulting to headache, vomiting). Children with astrocytoma usually have decreased memory, attention span, and motor abilities, but their intelligence, language, and academic skills remain unaffected. When metastasis occurs, it can spread via the lymphatic system, causing death to the patient, even when the primary tumor is well controlled.
Benign Astrocytoma Treatment
Resection of the tumor will generally allow an extension to survival for many years. In recent reports, the 5 year survival of affected patients has been over 90% with resected tumors. These tumors will eventually undergo malignant transformation and additional radiation therapy or chemotherapy will be necessary. Astrocytomas often come back even after treatment and are usually treated similar to the initial tumor, with sometimes more thorough chemotherapy or radiation therapy. In rare cases, the tumor creates two or more cell types, and treatment may kill one cell type while allowing the other survive, becoming more aggressive and immune to future treatments.