The patient went on to have a biopsy.
Histology
MICROSCOPIC DESCRIPTION: The sections show features of a densely cellular glial tumour. Most of the tumour cells are astrocytic with elongated, angulated and pleomorphic nuclei (>90%). A second minor population of intermixed neoplastic oligodendroglial cells is also present (<10%). These cells have round nuclei and perinuclear haloes. Some tumour cells extend to involve the cerebral cortex. Scattered mitotic figures are identified (more than 5 per 10 high power fields). Endothelial cell hyperplasia is absent. No necrosis is seen. The tumour cells are p53 positive. The Ki-67 index is 10-12%. MGMT and IDH-1 immunostains are negative. The features are those of anaplastic oligoastrocytoma.
DIAGNOSIS: Anaplastic oligoastrocytoma (WHO Grade III).