Primary lymphoma of the central nervous system. Clinicopathological study of experience at Stanford

The authors present 22 cases of primary lymphoma of the central nervous system (CNS) from Stanford University Medical Center. Fifteen other published series comprising 400 patients with this disease are also reviewed. Males were affected more often than females. The majority of patients were in the sixth decade of life. The most common presenting symptoms were headache, nausea, vomiting, and mental status changes. The most common presenting signs were hemiparesis and papilledema. An elevated protein concentration was the most common cerebrospinal fluid (CSF) abnormality. The CSF cytology was rarely positive prior to surgery. If a mass was seen on computerized tomography, it always enhanced with infusion of contrast material. On angiography, the tumor was generally seen as an avascular mass. The most and least common sites of involvement supratentorially were the frontal and occipital lobes, respectively. Infratentorially, the cerebellum was most often involved. Histologically, the most common tissue type according to the Rappaport and Working Formulation systems were diffuse histiocytic lymphoma and immunoblastic lymphoma, respectively. Therapy primarily involved surgery for biopsy or subtotal resection and radiation therapy. The majority of patients died, and the median survival time of those dying was distinctly shorter than the follow-up period of those patients still alive. This difference in survival time suggests that primary CNS lymphoma consists of more than one disease group. Statistical analysis of our series showed those patients with either a diffuse mixed lymphoma histology or an infratentorial location of disease had a poorer prognosis. These two factors cannot totally account for the division of cases into separate survival-related groups.