Brain Biopsy Frozen Section/Touch Prep
Brain Biopsy for Suspected Neoplasm • Is it Abnormal? • Is it Neoplastic? • What Type of Neoplasm is it? • What is the Neoplasm’s Grade?
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?
H&E CD20 EBER Ki67
Diagnosis: Malignant Lymphoma, High Grade, Diffuse Large B Cell Type, EBV positive
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
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
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
Quandary • There are no B lymphocytes normally in the CNS • How do you get Primary B cell lymphomas in CNS?
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
Argani’s rule of tumor pathology Stuff happens