Peripheral neuropathy in the course of progressive systemic sclerosis: light and ultrastructural study.

We present the case of a woman with progressive systemic sclerosis (PSS) in whom the usual symptoms were preceded by a rapidly progressive peripheral neuropathy. Few cases of peripheral nerve involvement have been described. For the first time we report an ultrastructural study of an affected peripheral nerve and muscle. In the sural nerve we found an almost complete loss of myelinated fibers. Schwann cells showed an abnormal hyperplasia of their basal membranes and structural signs of denervation. Spindle-shaped banded structures were seen in the cytoplasm of Schwann cells and in the endoneurium. On the basis of these ultrastructural data some hypotheses on the pathogenetic mechanism of this neuropathy are discussed.