British Journal of Neurosurgery (1994) 8, 427-432 ORIGINAL ARTICLE Primary lymphoma of the central nervous system B. SHEIKH & E. SIQUEIRA Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia Abstract Eleven patients with primary lymphoma of the central nervous system were seen in the King Faisal Specialist Hospital and Research Centre, Saudi Arabia, between 1986 and 1992. None had previously received immunosup- pressive therapy. All cases were confirmed by biopsy and histopathological studies. Of the eleven patients, six had debulking of the tumour, seven received radiation therapy and six received chemotherapy. This report confirms the very poor prognosis for patients with primary lymphoma of the central nervous system, with only a few long-term survivors. Key words: Lymphoma, CNS neoplasm. Introduction Lymphoma is rarely seen as a primary neo- plasm of the central nervous system (CNS), although its incidence appears to be increas- ing. 1 " 6,29 The incidence ranges from 0.5 to 3% of all CNS tumors, and 0.18 to 0.7% of all lymphomas. 6 ' 7 The age at diagnosis ranges from 2 months to 90 years, with most patients presenting in the fifth to seventh decades. 6 The lymphoma may occur at any site within the brain, but most frequently arises in the cerebral hemispheres. 6 ' 8 Although most pa- tients with primary CNS lymphoma are not immunodeficient, the lesion has been noted to occur with increasing frequency in patients who are immunologically suppressed, particu- larly those with organ transplants or who have acquired immunodeficiency syndrome. 6 ' 9 15 Summary of cases None of our patients had previously received immunosuppressive therapy. The clinical presentation was varied (Table I). The symp- toms relating to the disease were present from 2 weeks to 1 year before diagnosis. There were five males and six females. The age at onset ranged from 3 to 73 years with a mean age of 43.3 years. The frontal lobe was the most common site. The initial evaluation for all patients included complete blood count, rou- tine liver function studies and chest radiogra- phy. Each patient had one or more of the following neuroradiological studies: computed tomography (CT), magnetic resonance imag- ing (MRI) and cerebral angiography. Biopsy was performed by craniotomy in all patients except two: from one of these a stereotactic biopsy specimen was obtained; the other had a transnasal biopsy from the sphenoid sinus where the lesion was eroding from the sellar- parasellar region. Age and sex, tumour loca- tion, treatment and survival time are summa- rized in Table II. The treatment in most of the 427