All are true about primary CNS lymphoma except

Primary CNS lymphoma accounts for 2% of extra-nodal lymphomas and 1% of intra-cranial tumors. It is the most common CNS neoplasm in immunosuppressed individuals, including those with AIDS and immunosuppression after transplantation. Most primary brain lymphomas are of B-cell origin. In the setting of immunosuppression, the cells in nearly all such tumors are latently infected by Epstein-Barr virus. Overall, primary lymphomas of the CNS are aggressive, with relatively poor response to chemotherapy compared with peripheral lymphomas. Diffuse large-cell B-cell lymphomas are the most common histologic group. Within the tumor malignant cells infiltrate the parenchyma of the brain and accumulate around blood vessels. Reticulin stains demonstrate that the infiltrating cells are separated from one another by silver-staining material; this pattern, referred to as “hooping,” is characteristic of primary brain lymphoma.