Unknown All are true about primary CNS lymphoma except A Most primary brain lymphomas are of B-cell origin. B Anaplastic large cell lymphomas are the most common histologic group. C Hooping is characteristic of primary brain lymphoma. D Primary lymphomas of the CNS are aggressive 💡 Explanation All are true about primary CNS lymphoma except ✓ Correct Answer: B. Anaplastic large cell lymphomas are the most common histologic group.