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Diagnosis: Bifrontal butterfly S-shaped lesion consistent with glioblastoma multiforme.
Findings: Figure 1: Axial post Gadolinium T1 W1 of the brain reveals a large necrotic butterfly mass involving the corpus callosum with enhancing borders. There is no evidence of herniation.
Discussion: A butterfly lesion is a lesion which infiltrates across the corpus callosum. Thus this pathological process spreads from one hemisphere to another. The differential diagnosis of a butterfly lesion includes: glioblastoma multiforme (GBM), lymphoma, and demyelinating process. In this patient's case, the diagnosis was that of a GBM.
Symptoms can range from seizures to focal neurologic deficits to symptoms associated with increased intracranial pressure (headaches, nausea, vomiting, decreased visual acuity). Once a mass lesion is suspected, then an MRI with Gadolinium should be performed. This will usually show the classic ring enhancing (associated with angiogenesis occurring at the periphery of the tumor) lesion. However, definitive diagnosis is based on surgical biopsy.
Astrocytomas are the most common primary cerebral tumors affecting those in their fifth and sixth decade of life. These tumors represent 50% of all primary intracranial neoplasms. On histologic basis, these tumors are graded as: Grade 1---> low grade, grade II ---> anaplastic, grade III---> GBM. Of all astrocytomas, greater than half are GBM which are the least differentiated and most aggressive.
GBM tumors are treated with surgical resection and post-operative radiation. Nonetheless, this malignant process has a poor prognosis with the median survival being 8-10 months. The 1, 2, and 5-year survival rates are 30-44%, 8-12%, and 2.5-5%. The most common cause of death is reoccurrence of tumor at the original site.
References:
Grossman R, Loftus C. Principles of Neurosurgery. Lippincott-Raven, Philadelphia; 1999.
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