Marek Tomas, Howe B Matthew, Spinner Robert J
Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA.
Department of Radiology, University of Florida, Jacksonville, FL, USA.
Skeletal Radiol. 2025 May 1. doi: 10.1007/s00256-025-04932-3.
Neuromuscular choristoma (NMC) is a rare condition affecting peripheral nerves, most commonly the proximal sciatic nerve. It is characterized by the presence of muscle tissue within the nerve. Patients typically present with neuropathic symptoms. NMC is associated with the development of NMC-associated desmoid-type fibromatosis (NMC-DTF). In this study, we report findings of qualitative and quantitative MRI signal intensities to further expand on known MRI imaging features of NMC.
Retrospective analysis of NMC cases of the sciatic nerve from our institution was conducted. The sciatic nerve was selected as a model example due to its common involvement. Inclusion criteria were a confirmed NMC diagnosis and available MR exams. MRI signal intensities from the affected nerves and normal contralateral nerves were compared, normalized to muscle signal intensity for consistency across different MRI sequences.
Fourteen patients (8 men, 6 women) met the inclusion criteria. No significant differences in T1 or T2 signal intensities were found between NMC and unaffected nerves. However, NMC demonstrated significantly higher post-contrast signal intensities (p = 0.003) compared to unaffected nerves. These findings were consistent across the proximal and distal segments of the affected nerve.
Our study expands the understanding of MRI features in NMC. The increased post-contrast enhancement in NMC may serve as a useful diagnostic tool and could potentially play a role in detecting areas at risk for future DTF development. This highlights the importance of comprehensive imaging, including post-contrast sequences and ideally imaging of the entire course of the affected nerve.
神经肌肉错构瘤（NMC）是一种累及周围神经的罕见疾病，最常见于坐骨神经近端。其特征是神经内存在肌肉组织。患者通常表现为神经病变症状。NMC与NMC相关的硬纤维瘤病（NMC-DTF）的发生有关。在本研究中，我们报告了定性和定量MRI信号强度的结果，以进一步扩展已知的NMC的MRI成像特征。
对我院坐骨神经NMC病例进行回顾性分析。由于坐骨神经常受累，故将其选为典型示例。纳入标准为确诊的NMC诊断和可用的MR检查。比较患侧神经和对侧正常神经的MRI信号强度，并将其标准化为肌肉信号强度，以确保不同MRI序列之间的一致性。
14例患者（8例男性，6例女性）符合纳入标准。NMC与未受累神经之间在T1或T2信号强度上未发现显著差异。然而，与未受累神经相比，NMC在增强后信号强度显著更高（p = 0.003）。这些发现在患侧神经的近端和远端节段均一致。
我们的研究扩展了对NMC的MRI特征的理解。NMC增强后强化增加可能是一种有用的诊断工具，并可能在检测未来DTF发生风险区域中发挥作用。这突出了全面成像的重要性，包括增强后序列，理想情况下应对受累神经的整个行程进行成像。
