Current management of primary cerebral lymphomas

Primary cerebral lymphomas are an enigmatic disease, accounting for 6% of all brain tumors. They are characterized by a short clinical history and nonspecific neuroimaging findings. Immunohistochemical evaluation of biopsy material or cerebrospinal fluid provides the diagnosis in 90% of cases. Compared with other cerebral neoplasms, its incidence is growing both in immunocompetent and immunocompromised populations, raising problems of differential diagnosis and clinical approach of intracranial mass on computed tomograph or magnetic resonance imaging scan. The pathogenesis and molecular genetics of primary cerebral lymphoma are unknown, although putative involvement of Epstein-Barr virus is under discussion. In recent years, the disappearance of intermediate-grade histologic types suggests a shift in their biologic behavior. Despite controversy in the current therapy, the new therapeutic regimens appear to alter the natural history of this disease, because survival during the last decade has more than doubled and systemic metastases outside the central nervous system no longer occur. Primary cerebral lymphoma is probably a different disease in immunocompetent and AIDS populations, if we consider epidemiologic trends, clinical and radiologic presentations, pathogenesis, and prognosis.