Hypertrophic perineurial dysplasia in multifocal and generalized peripheral neuropathies

Two cases are described, one with a multifocal cranial and limb neuropathy of adult onset associated with optic neuropathy, and the other with a diffu se demyelinating neuropathy characterized by congenital cataract, mental re tardation and progressive lower limb paresis with an onset in childhood. Ex tensive investigation in both failed to establish the causation. No family history of similar disorder was obtained in either case. Nerve biopsy in bo th showed similar perineurial abnormalities, the endoneurium being compartm entalized by hypertrophic perineurial cells that exhibited dysplastic featu res. The appearances resemble those described in a previously reported case of multifocal neuropathy and probably represent an unusual but non-specifi c response to a peripheral neuropathy.