Rapid-progressive decrease of cognitive and physical functions in a B-cell non-Hodgkin's lymphoma patient treated with rituximab/bendamustine

History: A 71-year-old man with Richter's syndrome (transformation of chronic lymphocytic leukemia [CLL] to diffuse large B-cell lymphoma) was admitted to our hospital to get his second cycle of rituximab/bendamustin treatment. He had been diagnosed with Richter's syndrome three months earlier: a bulky tumor was seen on the backside of the stomach in a routine gastroscopy. Taking a biopsy had resulted in a major bleeding impossible to stop endoscopically. An emergency surgical multivisceral resection was performed. The first cycle of chemotherapy was administered about 4 weeks prior to the present appointment. Investigations: In the physical examination the patient showed a bad orientation and confusion together with a skinny habitus. The initially performed lab tests and a CT-Scan of the brain did not show a significant finding. A mini-mental-state-examination (MMSE) showed moderate cognitive impairment. In a psychiatric consultation the patient was diagnosed with reactive depression and a corresponding medication was given. After the second cycle of chemotherapy the patient's state of mind decreased markedly within days. Diagnosis, treatment and further course: The further diagnostic investigation (MRI of the brain, lumbar puncture) brought the diagnosis of progressive multifocal leukoencephalopathy. The administration of chemotherapy was stopped then. Three weeks after the diagnosis the patient died in the hospice. Conclusion: If a patient develops neurological or psychiatric symptoms during therapy with rituximab clinicians should be aware of the potential diagnosis of PML and initiate further investigations.