Sarcoidosis of the peripheral nerve: clinical, electrophysiological and histological study of two cases

Two cases of sarcoid polyneuropathy were diagnosed by histological examination of the nerve biopsy. The electrophysiological findings in both patients suggested a neuropathy of axonal type, confirmed by a morphological study of a sural nerve biopsy by light microscopy and on teased-fiber preparations. The sarcoid granulomas were multiple, especially in case 2; they were sparse in the epineurial and perineurial spaces and absent in the endoneurium, whose interstitial component contained cellular infiltrations of scattered macrophages. Blood vessel changes were a constant morphological feature. The mechanisms that possibly contribute to the pathogenesis of the sarcoid neuropathy are discussed in relation to previous reports.