INTRODUCTION

Lymphoma in CNS system is a type of Hodgkin lymphoma present in the brain, spine, CSF and eyes. In this lymphoma, cancer cells generate in lymph tissues of brain and spinal cord.  It has the best response to chemotherapy and radiotherapy¹. In spite of a high chemo- and radio sensitivity, results are not good because the blood brain-barrier restricts  the approach of most medicines to the CNS². It occurs 0.43 per 100,000 people and incidence is increased in patients with age and mostly occurs in older patients. It is more common in men than women^3,4.

B cell lymphoma is mostly appearing in patients with immune compromised patients e.g. AIDS and HIV etc⁵. The medical prospect for immune compromised patients is not good, immune compromised patients are those not having any immunodeficiency; there may be a chance of association with EBV (Epstein Bar Virus) or other DNA viruses⁶.On the other side, in immune competent patients PCNSL s mostly occurs in patients with age >50 yrs. The ratio of immune competent patients has increased 10 folds with PCNSLs. The exact cause is not known, but immunodeficiency is main cause⁷.