PERIPHERAL NERVE AND NEURO-MUSCULAR JUNCTION DISEASE: Edited by Claudia SommerReview and update in the diagnosis of peripheral nerve sheath tumorsMeyer, AndersAuthor Information Department of Pathology, University of Kansas School of Medicine, Kansas City, Kansas, USA Correspondence to Anders Meyer, MD, Department of Pathology, University of Kansas School of Medicine, 3901 Rainbow Boulevard, Mail Stop 3067, Kansas City, KS 66160, USA. Tel: +1 913 588 7090; e-mail: firstname.lastname@example.org Current Opinion in Neurology: October 2020 - Volume 33 - Issue 5 - p 575-586 doi: 10.1097/WCO.0000000000000857 Buy Metrics Abstract Purpose of review Although tumors with nerve sheath differentiation are vast, the main clinically significant problems faced by the pathologist are the separation of malignant peripheral nerve sheath tumors (MPNSTs) from histologic mimics, the diagnosis of neurofibromatous neoplasms with atypical features, and the separation of cutaneous neurofibromatous neoplasms from melanoma. This review briefly discusses a variety of common nerve sheath tumors and summarizes recent advances on these diagnostic fronts. Recent findings Much of recent work has focused on abnormalities in polycomb repressive complex 2, and the ways in which these abnormalities may be exploited in the diagnosis of MPNSTs. Progress has been made in the diagnostic and clinical understanding of atypical neurofibromatous neoplasms and low-grade MPNSTs. A number of reports have explored the diagnostic distinction between cutaneous neurofibroma and melanoma. Summary New discoveries show promise in the diagnosis of peripheral nerve sheath tumors, but challenges – old and new – remain. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.