Primary malignant lymphoma of the central nervous system presenting with ascites and pleural effusion

A 70-year-old woman was admitted to our hospital owing to ascites and pleural effusion. Though malignant cells (B-cell type lymphoma) were detected in both the ascites and pleural effusion, neither lymph node swelling nor a tumor was detected upon chest, abdominal and pelvic computed tomography (CT). After weekly THP-COP therapy for 8 weeks, the ascites and pleural effusion completely disappeared. Two years after the first admission, she was re-admitted because of a disturbance of consciousness, and a brain tumor was detected on CT scan. The immunohistological and genetic data for the brain tumor were identical to those of the malignant cells in the pleural effusion and ascites detected 2 years previously. Whereas the symptoms at onset of a primary lymphoma of the central nervous system (CNS) are usually neurological ones, in this rare case of primary CNS lymphoma, the symptoms at onset were the ascites and pleural effusion without neurological symptoms.