Progressive multifocal leucoencephalopathy (PML) is a progressive demyelinating
condition resulting from infection with the John Cunningham virus and precipitated
by immunocompromised states. The HIV pandemic, especially in sub-Saharan Africa, has
resulted in an increase in the number of patients presenting with PML. Imaging plays an
important role in diagnosis and the distribution of the disease is predominantly supratentorial.
Isolated posterior fossa involvement is a rare finding with very few cases described in the
literature. We present the largest case series of patients described in the literature, with isolated
posterior fossa involvement of PML, in HIV-positive patients.