1. Brain Biopsy Frozen Section/Touch Prep

2. Brain Biopsy for Suspected Neoplasm Is it Abnormal? Is it Neoplastic? What Type of Neoplasm is it? What is the Neoplasm’s Grade?

6. Brain Biopsy for Suspected Neoplasm Is it Abnormal? Yes Is it Neoplastic? Yes What Type of Neoplasm is it? What is the Neoplasm’s Grade?

7. TOUCH PREP-GLIOBLASTOMA MULTIFORME

8. TOUCH PREP-CNS LYMPHOMA

9. TOUCH PREP-PRESENT CASE

14. H&E EBER CD20 Ki67

15. Diagnosis: Malignant Lymphoma, High Grade, Diffuse Large B Cell Type, EBV positive

16. CNS Lymphomas Primary CNS Lymphoma –Immunosuppressed Patients –Immunocompetent Patients Secondary CNS Lymphoma –10% of systemic non-Hodgkin’s lymphomas involve CNS –Leptomeninges, epidural space are favored locations

17. Primary CNS Lymphoma Immunosuppressed Host –AIDS, s/p transplant, inherited immunodeficiency –95% EBV positive –Median survival=1 year Immunocompetent Host –Usually >60 years old –10% EBV positive –Median survival=3 years

18. Primary CNS Lymphoma Epidemiology –Incidence increased 10X worldwide due to AIDS Clinical –10% of patients have a history of another cancer –Respond dramatically to corticosteroids “ghost tumor”, “sentinel lesion” Radiology –Often homogeneously enhancing, periventricular Pathology –Most Diffuse Large B Cell Lymphoma –Hodgkins lymphoma=rare Treatment –Gross total resection not indicated –Biopsy for diagnosis followed by chemotherapy

19. Quandary There are no B lymphocytes normally in the CNS How do you get Primary B cell lymphomas in CNS?

20. Primary CNS Lymphoma: Possible Etiologies B cell transformed elsewhere in body that develops adhesion molecules specific for CNS endothelium Systemic lymphoma that is eradicated by immune system but is protected in CNS Clonal B cell neoplasm arising in polyclonal intracerebral inflammatory response

21. Argani’s rule of tumor pathology Stuff happens