AMR SeriesSelected Case From the Arkadi M. Rywlin International Pathology Slide Seminar: Atypical Thymoma With Rhabdomyomatous DifferentiationSuster, David MD*; Epstein, Howard D. MD†; Pearlstein, Daryl MD†; Suster, Saul MD‡Author Information *Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA †Departments of Pathology and Surgery, Hoag Memorial Hospital, Newport Beach, CA ‡Department of Pathology, Medical College of Wisconsin, Milwaukee, WI The authors have no funding or conflicts of interest to disclose. Reprints: Saul Suster, MD, Department of Pathology, Medical College of Wisconsin, 9200 W. Wisconsin Ave., Milwaukee, WI 53262 (e-mail: [email protected]). Advances In Anatomic Pathology: January 2019 - Volume 26 - Issue 1 - p 64-68 doi: 10.1097/PAP.0000000000000218 Buy Metrics Abstract Thymic epithelial neoplasms with foci of rhabdomyomatous differentiation are rare. A case is presented of a primary thymic epithelial neoplasm showing the features of an atypical spindle cell thymoma that contained foci of bland-appearing rhabdomyomatous cells. The histologic and immunohistochemical features of this tumor are discussed along with a review of the literature and the comments from the AMR members to the case. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.