Primary Central Nervous System Lymphoma Treatment Outcomes-a Decade's Experience from a Single Centre in Riyadh, Saudi Arabia
Authors: Tailor Imran K , Hussain Taimoor , Shakweer Wafa , Motabi Ibraheem H , Murtaza Ghulam , Zaidi Syed Ziauddin A. , Shehry Nawal F , AlGhamdi Mubarak S. , Bayoumi Yasser , Mudaibigh Samer 
Published: October 2019

Abstract
Background: Primary central nervous system lymphoma (PCNL) is relatively uncommon type of lymphoid malignancy and there is paucity of data on the incidence and prevalence, outcomes of these patients from Middle Eastern region.
Methods: We did a retrospective chart review of over 1200 patients diagnosed with lymphoma at our centre which is a tertiary care teaching hospital. We identified 10 patients (over the age of 18 years) with PCNL over a ten year period from 2005-2015.
Results: Out of 10 patients, 4 (40%) were males. Majority was over 45 years of age (70%). 8 of 10 (80%) patients had ECOG performance status of 3 or more. Histologically, 8 of 10 (80%) patients belonged to diffuse large B cell lymphoma, the rest were primary burkitt's lymphoma of the brain and primary T cell lymphoma respectively. Modalities of treatment received were Whole Brain Radiotherapy only (20%), High Dose Methotrexate (HD MTX) with High Dose Cytarabine (HD ARA C) (40%), both chemoradiation (40%), no treatment due to poor performance status (20%). Rituximab was given to all patients who received chemotherapy. Patient with Primary Burkitt's lymphoma received anthracycline containing combination chemotherapy with high dose methotrexate (RCHOPM) along with intrathecal chemotherapy. In the chemotherapy group 67% of patients achieved (4 out of 6) either partial remission (PR) or complete remission (CR) while 33% were refractory to treatment. Two patients (20%) received upfront radiotherapy only and achieved PR and CR respectively. Of the two patients who were refractory to upfront chemotherapy, one was salvaged with WBRT and is alive after 5 years, the other was lost to follow up. Of two patients who received upfront radiotherapy one was lost to follow up, the other relapsed after nearly 47 months later and was salvaged with Temozolamide and Rituximab, achieved partial remission and is well at the time of analysis. Of the evaluable 8 of 10 patients, at a median follow up of 31 months (Range1-66), 6 patients were alive and four without relapse or progression with an overall survival and progression free survival of 75% and 50% respectively.
Discussion: To our knowledge this is the first case series of PCNL from Saudi Arabia or Middle East. All the evaluable patients who received treatment are alive at the time of analysis. Our series shows PCNL is extremely rare malignancy even this part of the world and DLBCL remains the commonest histological form like in west. Radiotherapy remains valuable tool and can salvage patients refractory to chemotherapy achieving long periods of remission, its utility must not be underestimated even in elderly. Outcomes of patients at our institute are comparable with other centers, although numbers are small. Further detailed studies are planned to define exact incidence, prevalence, characteristics and outcomes of these patients from this region.

Disclosures
No relevant conflicts of interest to declare.