[Polyneuritis in chronic lymphoid leukemia. Ultrastructural study of the peripheral nerve (author's transl)].

A 75 years old man had a chronic lymphoid leukemia for 5 years. Within a period of three months he developed a polyneuritis. The biopsy of a peripheral nerve showed a large cellular infiltration by lymphocytes. The ultrastructural study shows in some Schwann cells disruption of the myelin. Their cytoplasm is invaded by a lymphocyte process as in Guillain-Barré. But in this case some of these invading lymphocytes show polygonal structures in their cytoplasm; that is sometimes seen in the proliferating cells of the chronic lymphoid leukemia.