title: Perineurioma (localized hypertrophic neuropathy).
abstract: Three patients with localized hypertrophic neuropathy ( LHN ) had a painless, slowly progressive mononeuropathy over many years, resulting in severe focal neurologic deficit. Grossly, the affected nerves showed a fusiform enlargement. Histologically, there was loss of nerve fibers, disorganization of the fascicular pattern, and proliferation of elongated cells with whorl formation. These cells exhibited no immunoreactivity for S-100 protein, and ultrastructural features set them apart from Schwann's cells. We conclude that LHN is not a disorder caused by hyperplasia of Schwann's cells but a benign peripheral nerve tumor of perineurial cell origin. This study also suggests that perineurial and Schwann's cells may not derive from the same precursor element.
mesh_terms: D000328:Adult; D006651:Histocytochemistry; D006801:Humans; D007120:Immunochemistry; D008297:Male; D008854:Microscopy, Electron; D009380:Neoplasms, Nerve Tissue / Q000473:pathology* / Q000648:ultrastructure; D009455:Neurofibroma / Q000473:pathology* / Q000648:ultrastructure; D009474:Neurons / Q000648:ultrastructure; D010524:Peripheral Nervous System Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D009418:S100 Proteins / Q000276:immunology
chemical_list: D009418:S100 Proteins