Abstract: Objective To investigate the incidence, clinical and radiological features, treatment and prognosis of immunocompetent patients with primary central nervous system lymphoma(PCNSL) through analyzing the clinical data. Methods One hundred and twenty-five consecutive patients certified histologically through craniotomy and/or stereotaxic biopsy were reviewed restropectively and underwent a systematic work-up including radiographs and/or computerized scan(CT), ultrasound etc from August, 1995 to October, 2006 at Tiantan Hospital, Beijing. Data were inputted into the database set up by Epidata 3.02. Statistical analysis was performed with SPSS 12.0. Results There were 82 men and 43 women, 96 cases had single lesion and 29 had multiple lesions. They had surgical treatment at the age of 2～75 years. The main presentation was related to increased intracranial pressure. Total resection were achieved in 69 cases, subtotal in 37 cases, partial in 8 cases, stereotactic biopsy in 11 cases. Postoperatively, combined radiotherapy and chemotherapy were given in 81 cases, radiotherapy alone in 21 cases, chemotherapy alone in 15 cases. Eight-nine cases have been followed up. At the time of last contact, 62 patients had died, all but five from PCNSL disease or from complications due to its treatment. The median survival time was 13.62 months. Twenty-seven patients were still alive at the last contact. Conclusion PCNSL is a rare highly malignant CNS tumor in the general immunocompetent population and is a very aggressive neoplasm with a poor prognosis. CT scan generally provide results that are suggestive but not conclusive for PCNSL in immunocompetent patients, but MRI scan with rim enhancement is specific for it. Because of the location and the infiltrating nature of the lesions,surgical resection alone is of no good to improve the survival of patients with PCNSL. Surgery combined with chemotherapy and radiotherapy should be the main treatment options. Controversy continues regarding prognostic factors in PCNSL in immunocompetent patients. The following, however are the most widely accepted factors: the age of onset performance status, location of the tumors.

Key words: lymphoma, central nervous system, treatment