Primary central nervous system lymphoma--a hospital based study of incidence and clinicopathological features from India (1980-2003).

Over the last two decades, an increase in the incidence of PCNSL cases has been reported in the West, both among immunosuppressed and immunocompetent patients. The present study was undertaken to assess the trend of incidence of PCNSL cases in India. To the best of our knowledge, only a single such report is available from India. All biopsy proven PCNSL cases obtained from the Neurosurgical databases of two large referral hospitals, one in Northern India (AIIMS, New Delhi) and another in Southern India (NIMHANS, Bangalore) from the period 1980 to 2003, were reviewed. Immunophenotyping was done and relevant clinical details collected. Appropriate statistical analysis was done to assess any change in trend of incidence or age at presentation. PCNSL cases constituted 0.95% and 0.92% of the total intracranial neoplasms at AIIMS and at NIMHANS, respectively. The mean age for cases diagnosed at AIIMS was 44.35 years, while that for NIMHANS was 39.51 years. Statistical analysis to evaluate any change in trend either of incidence or of age at presentation, over the study period, did not reveal any significant change. All the cases occurred in immunocompetent patients, except one case of HIV positive at NIMHANS, and one case of renal transplant at AIIMS. Frontal lobe was the most common site of involvement. Majority of the cases were diffuse, high grade, large cell lymphoma, B-cell immunophenotype. Thus, this multicentric hospital based study did not reveal any increase in incidence of PCNSL cases in India over the past 24 years. Further, in contrast to the West, majority of the cases in this Indian study were immunocompetent and a decade younger than in the West. The association of PCNSL with HIV/AIDS has been low in India, possibly due to early death in AIDS on account of opportunistic infections.