Monarch Disease Ontology entry MONDO_0002547 (nerve sheath neoplasm) is a benign or malignant neoplasm arising from the perineural cells in the sheaths surrounding the nerves. Representative examples include neurofibroma, schwannoma, and malignant peripheral nerve sheath tumor. Also known as: neoplasm of nerve sheath, neoplasm of the nerve sheath, nerve sheath tumor, nerve sheath tumour, peripheral nerve sheath neoplasm, tumor of nerve sheath, tumour of nerve sheath.