A 62-year-old woman with arterial hypertension and diabetes mellitus presented with a 1-month history of rapidly progressive memory impairment for recent events and topographic disorientation. Examination revealed temporospatial disorientation and poor performance in delayed recall tests, without any other significant clinical or neurological findings.
The patient had a mean corpuscular hemoglobin concentration of 14.3 g/dL (to convert to grams per liter, multiply by 10), a white blood cell count of 10 600/μL (to convert to ×109/L, multiply by 0.001), a platelet count of 132 × 103/μL (to convert to ×109/L, multiply by 1.0), and a lactic dehydrogenase level of 511 U/L (to convert to microkatals per liter, multiply by 0.0167). Human immunodeficiency virus infection was ruled out. Magnetic resonance imaging disclosed bilateral infiltrating lesions in both hippocampi, extending to the adjacent choroid plexuses of the inferior horn of the lateral ventricles. There was extensive perilesional edema and some associated subependymal enhancement (Figure 1).1,2 Cerebrospinal fluid analysis showed predominantly lymphocytic pleocytosis (38 cells/μL), a protein level of 900 mg/dL, and a glucose level of 80 mg/dL (to convert to millimoles per liter, multiply by 0.0555) and was negative for neoplastic cells. Stereotactic biopsy of the right temporal lobe revealed diffuse large B-cell lymphoma (Figure 2).3,4 Cervical, thoracic, abdominal, and pelvic computed tomographic scans were normal. Bilateral iliac crest bone marrow biopsy specimens were negative for neoplastic infiltration.