Paraffin and cryosections showed no immunostaining for light chain, no amyloid deposits and no vascular changes. Focal collection of mature lymphocytes (Image 01) in epineurium could not be immunophenotyped because they occurred so inconsistently.
Semithin resin sections with toluidine blue revealed a reduction in the number of myelinated fibers and slight axonal degeneration (Images 02, and 04). Many of the surviving myelinated fibers contained osmophilic bodies in the Schwann cell cytoplasm (Images 02 and 04). The normal sural nerve is illustrated in Image 03 (oil immersion). Most of the smooth cells of a large epineurial vessel showed small osmophilic bodies in the perinuclear region as well as vacuolar change (Image 05).
Ultrastructural examination confirmed the presence of cytoplasmic lamellar inclusions in the schwann cell cytoplasm, (Images 06 and 07). Close examination show the dimorphism of the inclusions made up of both curvilinear bodies and laminated (myeloid) osmophilic material in smooth muscle cell (Image 08).