text: <unk> s are mixed tumors that arise from the proliferation of both oligodendrocytes and astrocytes. Genes associated with the pathogenesis of<unk>  and anaplastic<unk>  include IDH1, p53, EGFR, ATRX, EGFR, PTEN, MGMT, CIC, and FUBP1. 30-70% of<unk> s show loss of heterozygosity (LOH) of 1p and 19q. On gross pathology,<unk>  is characterized by a soft, well-defined, grey-tan, mucoid or hemorrhagic, calcified mass with or without necrosis, which may expand the gyrus and cause blurring of the grey-white junction. On microscopic histopathological analysis,<unk>  is characterized by highly cellular lesions composed of both oligodendroglial and astrocytic components. In addition to the histological features of<unk> , anaplastic<unk>  also has significant or brisk mitotic activity, marked cytologic and nuclear atypia, necrosis, apoptosis, and microvacular proliferation.<unk>  is demonstrated by positivity to tumor markers such as MAP2, GFAP, IDH1, OLIG-1 protein, OLIG-2 protein, and Iba-2 protein.
option_0: Oligoastrocytoma pathophysiology
option_1: Astrocytoma pathophysiology
option_2: Meningioma pathophysiology
option_3: Schwannoma pathophysiology
option_4: Ameloblastoma pathophysiology
option_5: Oligodendroglioma pathophysiology
option_6: Glioblastoma multiforme pathophysiology
option_7: Glioma pathophysiology