Case ReportMolecular Analysis of a Patient With Neurofibromatosis 2 (NF2) and Peritoneal Malignant MesotheliomaGlass, Carolyn MD, PhD*; Sholl, Lynette M. MD†; Landgraf, James R. MD‡; Chirieac, Lucian MD†; Roggli, Victor L. MD*Author Information *Department of Pathology, Duke University Medical Center, Durham, NC †Department of Pathology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA ‡Department of Pathology, Anderson Hospital, Maryville, IL Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article. Correspondence: Victor L. Roggli, MD, Department of Pathology, Duke University Medical Center, M255 Davison Building, Duke Box 3712, 200 Trent Drive, Durham, NC 27710 (e-mail: email@example.com). Online date: September 20, 2019 The American Journal of Surgical Pathology: February 2020 - Volume 44 - Issue 2 - p 288-292 doi: 10.1097/PAS.0000000000001359 Buy Metrics Abstract Neurofibromatosis type 2 (NF2), an inherited disorder associated with multiple inherited schwannomas, meningiomas and ependymomas is caused by an autosomal dominant, likely loss of function germline mutation of the NF2 gene. Interestingly, biallelic NF2 gene inactivation is one of the most common mutations associated with the development of malignant mesothelioma (MM), a highly fatal malignancy that arises in the pleura and less frequently in the pericardium, peritoneum, and tunica vaginalis. It has been proposed that NF2 patients could potentially be at increased risk of developing MM. However, patients with inherited NF2 rarely develop MM. To date, only 2 cases describing patients diagnosed with both have been reported in the literature. Here, we describe the third case and for the first time, also provide molecular evidence that a “second hit” involving a somatic mutation is likely required to trigger the development of MM in this rare cohort. In our patient diagnosed with NF2 at age 25 who developed an aggressive peritoneal MM 15 years later, we identified a germline NF2 mutation and somatic mutations including BAP1. Of clinical relevance, our case supports a germline NF2 mutation may not necessarily be more susceptible to develop mesothelioma without a “second hit” mutation. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.