Lymphocyte inclusions in the juvenile type of generalized ceroid-lipofuscinosis. An electron microscopic study.

Peripheral blood lymphocytes exhibiting cytoplasmic vacuoles from eight patients with the juvenile type of generalized ceroid-lipofuscinosis were investigated by electron microscopy. Osmiophilic inclusions could be demonstrated in the vacuoles and occasionally in the cytoplasm proper, revealing a fingerprint-like ultrastructural pattern or a less defined dense granular material, sometimes with an osmiophobic component adjoined. The inclusions are compared with those demonstrated in seven of the cases by earlier investigations of rectal biopsies in a variety of cell types, mainly in nerve cells. Discrimination is attempted between the lymphocyte inclusions and "parallel tubular arrays" regarded as representing a regular lymphocyte constituent.