Nonenhancing secondary central nervous system lymphoma.

Central nervous system (CNS) lymphoma is an aggressive neoplasm. Incidence is increasing, partly due the use of immunosuppressive drugs and AIDS-related immunodeficiency. Nonenhancing lesions in CNS lymphoma are very rare, and often cause diagnostic delay. We report a case of nonenhancing secondary CNS lymphoma. We present a 77-year old man with a medical history of nine attacks of transient pancytopenia during the last five years, associated with fever, elevated lactate deshydrogenase (LDH), and hepatosplenomegaly. Bone marrow aspiration and liver biopsy were normal. In order to treat pancytopenia of unknown origin, oral corticosteroid treatment was started during the last attack of pancytopenia, three month before admission. The patient presented with progressive drowsiness and gait unsteadiness since one month. Brain MRI showed brainstem, bitemporal, periventricular, and meningeal abnormalities (Fig.). Lumbar puncture showed 150 lymphocytes/mm. Anatopathological examination of CSF revealed a large B-cell lymphoma. A diagnosis of secondary brain lymphoma was made after bone marrow aspiration showed the presence of a diffuse large B-cell lymphoma (centroblastic variant). Lack of typical gadolinium enhancement of brain lesions in our patient may be related to the intake of corticoids.