Progressive multifocal leukoencephalopathy in a patient with B-cell lymphoma during rituximab-containing chemotherapy: case report and review of the literature

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyomavirus. We describe a rare case of PML in a 48-year-old female patient with diffuse large B-cell lymphoma who received rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy. While she was undergoing five cycles of R-CHOP, she noticed gradually progressive neurological symptoms, such as slurred speech and gait disturbance, and she eventually developed high-grade fever. She also developed Pneumocystis jiroveci pneumonia. The neurological symptoms deteriorated thereafter, and she developed spastic quadriparesis and bulbar palsy. Magnetic resonance imaging showed hyperintensity within the right cerebellar hemisphere on T2-weighted images. Polymerase chain reaction-based tests of the cerebrospinal fluid revealed the presence of the JC virus. Despite intravenous and intrathecal cytarabine treatment, the patient died of PML 5 months after it was diagnosed. Retrospective analysis of her laboratory data showed that her CD4+ T-cell count before R-CHOP therapy had decreased to 68 mu L<-1 Thus, when administering rituximab-containing chemotherapy, even to patients with no prior history of opportunistic infections, attention should be paid to the potential occurrence of PML, particularly in patients with low CD4+ T-cell counts.