Histopathological Study of Peripheral Neuropathies on Nerve Biopsy: A Cross-sectional Study

Abstract

Introduction: Peripheral neuropathy is common in clinical practice, with a reported prevalence of 2.4% in the general population. There are numerous aetiologies for peripheral neuropathy like diabetes, ischaemia, vasculitis, inflammatory demyelinating disorders, nutritional deficiencies, paraproteinemic disorders, paraneoplastic syndromes, toxic exposures, and hereditary neuropathies. An exhaustive haematological, biochemical, and serological work-up, cerebrospinal fluid evaluation, electrodiagnostic tests, and nerve biopsy are required when overlapping clinical features present a diagnostic challenge. Aim: To analyse the histopathological characteristics of nerve biopsies in individuals with peripheral neuropathy. Materials and methods: This cross-sectional study was conducted in the Department of Pathology at Kasturba Medical College from January 2011 to December 2016. Nerve biopsies received in the Department of Pathology, Kasturba Medical College and Hospitals in the Ambedkar Circle and Attavar area, as well as at Government Wenlock Hospital, Mangaluru, Karnataka, India were studied. Clinical and laboratory data were collected from biopsy requisition forms and patient case records from the aforementioned hospitals. Results were presented in numbers and percentages. Results: A total of 134 nerve biopsies were included in the study. The age range of all cases studied was 7-86 years, with a mean age of 51.8 years. The study population consisted of 63.4% males and 36.6% females, resulting in a male-to- female ratio of 1.7:1. Vasculitic Neuropathy (VN) accounted for 38.1% cases, followed by chronic inflammatory neuropathies (21.7%) and Diabetic Neuropathy (DN) (12.6%). Other diagnosis included ischaemic neuropathy (6.7%), Hereditary Motor and Sensory Neuropathy (HMSN) (3.7%), subacute inflammatory demyelinating neuropathy (3.0%), as well as two cases each of Hansen’s neuritis, amyloid neuropathy, and acute inflammatory demyelinating neuropathy (1.5% each). One case of toxic neuropathy (0.7%) was identified, while 9.0% of cases displayed histological features that were either non specific or not characteristic of any specific diagnosis. Conclusion: Vasculitic neuropathy was found to be the most common aetiology of peripheral neuropathy, followed by Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and DN. The histopathological examination of nerve biopsies is a useful tool in distinguishing between diseases with overlapping clinical features, confirming or excluding vasculitis, and diagnosing hereditary conditions in settings where genetic testing is unavailable or unaffordable.