Original ArticlesALK-positive Large B-cell Lymphoma A Clinicopathologic Study of 26 Cases With Review of Additional 108 Cases in the LiteraturePan, Zenggang MD, PhD*; Hu, Shimin MD, PhD†; Li, Min MD, PhD‡; Zhou, Yi MD, PhD§; Kim, Young S. MD∥; Reddy, Vishnu MD¶; Sanmann, Jennifer N. PhD, FACMG#; Smith, Lynette M. PhD**; Chen, Mingyi MD, PhD††; Gao, Zifen MD‡; Wang, Huan-You MD, PhD‡‡; Yuan, Ji MD, PhD§§Author Information *Department of Pathology, University of Colorado Denver, Aurora, CO †Department of Hematopathology, MD Anderson Cancer Center, Houston, TX §Department of Laboratory Medicine, University of Washington, Seattle, WA ∥Department of Pathology, City of Hope National Medical Center, Duarte ††Department of Pathology, University of California Davis, Sacramento ‡‡Department of Pathology, University of California San Diego, La Jolla, CA ¶Department of Pathology, University of Alabama at Birmingham, Birmingham, AL #Human Genetics Laboratory **Department of Biostatistics §§Department of Pathology and Microbiology, University of Nebraska Medical Center, NE ‡Department of Pathology, Peking University Health Science Center, Beijing, China 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: Ji Yuan, MD, PhD, Department of Pathology and Microbiology, 983135 Nebraska Medical Center, Omaha, NE 68198-3135 (e-mail: [email protected]). The American Journal of Surgical Pathology: January 2017 - Volume 41 - Issue 1 - p 25-38 doi: 10.1097/PAS.0000000000000753 Buy SDC Metrics Abstract Anaplastic lymphoma kinase–positive large B-cell lymphoma (ALK+ LBCL) is a rare, aggressive subtype of diffuse large B-cell lymphoma with characteristic ALK rearrangements. Diagnosis of ALK+ LBCL can be challenging because of its rarity, unique morphologic characteristics, and unusual immunophenotypic features, which significantly overlap with other hematologic and nonhematologic neoplasms. The purpose of this study is to further explore the clinicopathologic features of ALK+ LBCL to ensure the awareness and accurate diagnosis of this entity. We retrospectively reviewed the data from 26 cases in our institutions and additional 108 cases from the literature. ALK+ LBCL typically occurred in the lymph nodes of young and middle-aged, immunocompetent patients. The medium age was 35 years with a male to female ratio of 3.5:1. Vast majority of cases showed immunoblastic and/or plasmablastic morphology. All cases expressed ALK protein with a cytoplasmic granular pattern in most of them. Common B-cell markers (CD20, CD79a, and PAX5) were typically negative, but the tumor cells mostly expressed 2 B-cell transcriptional factors, BOB1 and OCT2. The 5-year overall survival (OS) was 34%, and the median survival was 1.83 years. In patients with stage III/IV disease, the 5-year OS was only 8%. Moreover, patients below 35 years of age had a significantly better OS than those aged 35 years or above. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.