Intracranial neuromuscular choristoma: report of a case with literature review

Neuromuscular choristoma (NMC), also called neuromuscular hamartoma or nerve rhabdomyoma, is a rare lesion of the spinal and cranial nerves composed of skeletal muscle intimately associated with nerve fibers. Its origin has not been precisely clarified and a malformative event, resulting from aberrant differentiation or a true neoplastic growth, have been proposed by authors. We hereby present a cerebellopontine angle NMC enlarging the eighth cranial nerve in a 3-year-old child, that histologically appeared composed of a large amount of striated muscle mixed with nerve fibers. We also provide a review of the intracranial NMC cases reported in the literature and an analysis of proposed hypotheses to explain the presence of muscle cells in nerve trunks.