Abnormal proliferation of intraergastoplasmic microfilaments in myelinated schwann cells: ultrastructural study of two cases.

We report the ultrastructural findings in superficial peroneal nerve biopsies in two patients, one with idiopathic sensory neuropathy and the other with the Guillain-Barré syndrome and Hodgkin's disease. In addition to demyelination, there was an intense proliferation of microfilaments within numerous vesicles of the endoplasmic reticulum of a great number of myelinated Schwann cells. This abnormality does not appear to have been previously reported in the literature. The mechanisms responsible for this finding are unknown.