Processing of nerve biopsies: A practical guide for neuropathologists

Joachim Weis,Jean-Michel Vallat,Claudia Sommer,Sebastian Brandner,Martin Lammens

doi:10.5414/np300468

Abstract

Nerve biopsy is a valuable tool in the diagnostic work-up of peripheral neuropathies. Currently, major indications include interstitial pathologies such as suspected vasculitis and amyloidosis, atypical cases of inflammatory neuropathy and the differential diagnosis of hereditary neuropathies that cannot be specified otherwise. However, surgical removal of a piece of nerve causes a sensory deficit and – in some cases – chronic pain. Therefore, a nerve biopsy is usually performed only when other clinical, laboratory and electrophysiological methods have failed to clarify the cause of disease. The neuropathological work-up should include at least paraffin and resin semithin histology using a panel of conventional and immunohistochemical stains. Cryostat section staining, teased fiber preparations, electron microscopy and molecular genetic analyses are potentially useful additional methods in a subset of cases. Being performed, processed and read by experienced physicians and technicians nerve biopsies can provide important information relevant for clinical management.

Highlights

With a prevalence of 1 : 200 [1], peripheral neuropathies (PNP) encompass one of the largest disease groups among the neurological disorders
Nerve biopsy is a valuable tool in the diagnostic work-up of peripheral neuropathies
Serial sectioning of 3 – 4 levels or alternatively 30 consecutive sections is recommended if an inflammatory, especially a vasculitic neuropathy is suspected, but has not been detected in the initial sections

Summary

Introduction

With a prevalence of 1 : 200 [1], peripheral neuropathies (PNP) encompass one of the largest disease groups among the neurological disorders. Even though clinical history and examination combined with electrophysiological and laboratory methods often uncover the cause of PNP, a substantial number of cases remain unsolved and stay without definite diagnosis after careful application of these methods In such situations, nerve biopsies have been a method of choice for decades to classify PNPs and to find clues to uncover their etiology. Nerve biopsies have been found to be useful to detect pathological immunoglobulin deposits [1] They can provide guidance in the differential diagnosis of hereditary neuropathies with. In selected cases with suspected focal lesions, biopsies of larger, mixed sensory and motor nerves guided by MR imaging and/or sonography can be performed to detect and classify inflammation (focal neuritis), neoplasias (nerve sheath tumors, perineuriomas, neurolymphomatosis and others) and hereditary hypertrophic neuropathies

Surgical procedures

Findings

Conclusions and outlook