Progressive Multifocal Leukoencephalopathy: A rare infectious complication following allogeneic hematopoietic cell transplantation (HCT)

Progressive multifocal leukoencephalopathy (PML), a demyelinating disorder caused by brain infection with JC virus, is a neurological complication of immunocompromised states and immunosuppressive therapies. While most commonly seen in the HIV/AIDS population, patients with hematologic malignancies are also at risk following treatment protocols including monoclonal antibodies such as rituximab and after hematopoietic stem cell transplantation. Here, we present the case of PML following allogeneic HCT that highlights potential diagnostic difficulties. We also review the literature regarding PML following HCT and described therapies employed to attempt to treat this disorder.