"Pardon My Language": The Curious Case of a Bloody Sandwich and the John Cunningham Virus Reactivation in the Era of Immunomodulatory Drugs.

Progressive multifocal leukoencephalopathy (PML) is a rare diagnosis associated with high mortality in different clinical settings. PML has been attributed to the reactivation of the John Cunningham (JC) virus (JCV). JCV typically affects patients with HIV/AIDS, solid organ and hematological malignancies, and those under treatment with immunomodulatory drugs (IMiDs) like pomalidomide.