Neuromuscular choristoma of peripheral nerve: a systematic review of the literature and institutional cases

Neuromuscular choristoma (NMC) is a rare developmental peripheral nerve lesion characterized by muscle tissue within the affected nerve and a recognized association with NMC-associated desmoid-type fibromatosis (NMC-DTF). Its clinicoradiologic profile and comparison between published and institutional cases remain incompletely defined. A systematic review of the peripheral nerve NMC literature, excluding central nervous system cases, was performed in accordance with PRISMA principles using PubMed and Google Scholar. Published cases meeting imaging and/or biopsy-based diagnostic criteria were compared with retrospectively identified institutional cases. Demographic, clinical, imaging, pathologic, and molecular variables were extracted. Twenty-nine articles reporting 48 literature cases and 30 institutional cases were included. In both cohorts, NMC most commonly involved large proximal nerves, particularly the sciatic nerve and brachial plexus, and was frequently associated with weakness, nerve-territory undergrowth, and NMC-DTF. Institutional cases were more likely to undergo MRI and PET imaging, and be managed without biopsy. MRI was performed in all institutional cases and in 35 literature cases, whereas PET was used in 12 and 2 cases, respectively. CTNNB1 alterations were identified in both NMC and NMC-DTF. NMC is a rare but distinctive lesion with a recognizable clinicoradiologic phenotype, most commonly affecting the sciatic nerve. Contemporary diagnosis appears increasingly imaging-based, supporting a no-touch approach and reinforcing the biologic link between NMC and NMC-DTF.