Ultrastructural pathology of human T-cell lymphotropic virus type I encephalomyelopathy in a white patient with adult T-cell leukemia/lymphoma.

A white patient with human T-cell lymphotropic virus type I (HTLV-I)-associated adult T-cell leukemia/lymphoma for 10 years died 4 months after the onset of spastic myelopathy. Ultrastructurally, the neuropathologic findings consisted of dystrophic neurites (spheroids) filled with neurofilaments or electron-dense bodies, intense astrocytic reaction with abundant formation of corpora amylacea, and multilamellar bodies. Demyelination and spongiform change were absent. Viruslike particles resembling HTLV-I were detected adjacent to brain endothelial cells.