Diffuse axonal swellings in a case of acquired immunodeficiency syndrome.

We report a case of a 25-year-old woman affected by the acquired immunodeficiency syndrome in whom the neuropathologic examination disclosed the presence of diffuse axonal swellings in the brain stem and in selected areas of cerebral hemispheres. These lesions, although microscopically similar to those previously described as focal pontine leukoencephalopathy, differ in that their distribution was wider, there was an absence of associated necrosis of the adjacent nervous tissue, and there was a lack of calcification. It is suggested that axonal swellings represent a nonspecific reaction of the central nervous system to infection by opportunistic agents and/or human immunodeficiency virus in patients with the acquired immunodeficiency syndrome.