Histopathological patterns in meralgia paraesthetica: insights from lateral femoral cutaneous nerve neurectomies

Abstract

Background: Surgical treatment of entrapment neuropathies based on nerve decompression. A different approach applies in the case of meralgia paraesthetica affecting the purely sensory lateral femoral cutaneous nerve (LFCN). Established treatment options include both decompression and LFCN neurectomy. The latter not only provides symptomatic relief but also enables proper histopathological analysis, offering deeper insight into the etiopathogenesis of meralgia paraesthetica.

Material and method: 14 LFCNs neurectomies were performed 13 patients at our department between 2015 and 2022. Histopathological specimens were available for 12 LFCNs. We analyzed selected pathological features, for example interfascicular multifocal fiber loss, perivascular epineurial inflammation, perineurium thickness (μm), collagen content (%).

Results: Based on histopathological findings, patients were divided into three groups according to symptom duration: <1 year, 1-3 years, and >3 years. In the <1 year group, interfascicular multifocal fiber loss and loss of large myelinated fibers with signs of regeneration were observed, while perineurial thickening and subperineurial edema were absent. In the 1-3 year group, all three features were present in the majority of cases, except one (20 %) lacking perineurial changes. In the >3 year group, neither fiber loss nor regeneration was observed, while perineurial thickening and subperineurial edema were present in 50 % of cases. No correlation was found between the histopathological patterns and clinical parameters.

Conclusion: LFCN neurectomy provided a unique opportunity to examine the histopathological features of entrapment neuropathy. Our findings indicate that histopathological changes correlate primarily with the duration of symptoms rather than with the severity of clinical presentation or the degree of postoperative improvement.

Keywords: Histopathological insight, interfascicular multifocal fiber loss; Loss of large myelinated fibers with evidence of regeneration; Meralgia paraesthetica; Perineurial thickening and subperineurial edema; Perivascular epineurial inflammation.