Posterior Fossa Glioblastoma, Case Report, and Reviewed Literature

Glioblastomas multiformes (GBMs), are the most common primary malignant tumors of the Central Nervous System. Frequently located in supratentorial topography, infratentorial location is rare, around 0-3.4% of primary GBMs. The diagnosis of these tumors is uncommon in adults, few cases have been reported, being even more infrequent in elderly patients. The most typical clinical presentation is a rapidly growing posterior fossa lesion, increased intracranial pressure, and cerebellar signs associated with the mass and perilesional edema. Clinical presentation, computed tomography (CT), and magnetic resonance imaging (MRI) provide useful information about the possible diagnosis but are not definitive. We describe a clinical case, 76 years old female with a clinical history of hypertension, depressive syndrome, and dyslipidemia. Started progressively with ataxy, imbalance, and vertigo. Brain CT shows an intra-axial, infiltrative lesion in the superior and middle vermis. MRI presents a heterogeneous lesion in the superior and median vermian region of the cerebellum with ring enhancement and central necrotic area. Was performed a middle suboccipital approach, corticectomy in the superior vermis. The intraoperative histological study reveal a high-grade malignancy astrocytoma, which was released through a subtotal resection. The histological result was a high-grade astrocytoma, grade IV in WHO classification. Four weeks after the surgery the patient started treatment with chemotherapy and radiotherapy. The main point of this case is the atypical location of the tumor.  These lesions are rare in this location but they will do considering the differential diagnosis of posterior fossa tumors. However, the most frequent lesions with high percentages of incidence are metastatic lesions.