Tumors of Blood Cell Origin

• Lymphoma – usually B cell, diffuse, have concentric reticulin
• Primary CNS lymphoma – parenchymal, subependymal, or subpial
• Account for 1% of intracranial tumors
• Increased incidence in immunocompromised patients (AIDS, transplant patients, chemotherapy patients, chronic steroid users)
• 50% have multiple lesions at presentation
• always a high-grade B cell lymphoma (no B cells in normal brain)
• systemic lymphoma is rare at time of presentation (25% have systemic disease at time of recurrance)
• high mitotic index
• immunocompitent patients – diffusely enhancing single or multiple masses (at least one in contact with CSF space)
• immunocompromised patients – appearance varies
• no benefit to surgery except emergency decompensation
• 20-25% have malignant cells in CSF
• 15% have ocular involvement
• steroids are cytotoxic (not true for immunosuppressed)
• Radiology:  Multiple hyperdense lesions with homogeneous (or occasional ring) enhancement tending to be deep white/gray matter (thalamus, basal ganglia, periventricular white matter)
• treated with high-dose methotrexate (median survival 4 years)
• may use adjuvant radiation (may cause dementia in older patients)
• retuxin is anti-CD20 antibody - not known if it changes overall survival, used in recurrence
• may recur at distant site (local treatment does not help)
• immunosuppressed patients - tumor associated with EBV
• prognosis depends on state of immune system
• transplanted patients have better prognosis if immunosuppression stopped
• Prognosis:  Rapid recurrence and death are usualUsually 60 year old unless immunosuppressed
• 30% multiple
• Metastatic lymphoma – usually meningeal or spinal epidural; can be intravascular causing stroke and dementia
• Hodgkin’s disease – binucleated Reed-Stirnberg cells are seen
• Plasmacytoma/Multiple Myeloma – 70% involve skull
• Mixture large/small cells
• Russel bodies – eosinophilic intracytoplasmic bodies filled with reticulin
• Waldenströms Macroglobulinemia – plasma cells in liver, spleen, lymph nodes; no lytic lesions; 25% have neurological problems (autonomic, stroke, subarachnoid)
• Heavy Chain disease
• Primary amyloidosis (light chains)
• Histiocytosis X – usually involved bone but 25% extraskeletal (most of these have intracranial component) – associated with diabetes insipidus; EM shows birbeck bodies (tennis-racket shaped) in cytoplasm
• Leterer-Siwe disease – acute disseminated histiocytosis in young children; death in 2 years
• Multifocal histiocytosis – chronic, recurrent, associated with respiratory infections; histiocytes found in lymph node, liver, spleen, bone, pituitary, hypothalamus; Hans-Schuller-Christian disease consists of lytic bone disease, exophthalmos, diabetes insipidus
• Eosinophilic granuloma – solitary benign painful; lytic with clear margins (no sclerotic rim); full thickness of skull; can be found in brain/spinal cord/dura
• Chloroma (leukemia) – likely to hemorrhage