Anaplastic large cell lymphomas (ALCLs) comprise a group of CD30-positive non-Hodgkin lymphomas that generally are of T-cell origin and share common morphologic and phenotypic characteristics. The World Health Organization recognizes 3 entities: primary cutaneous ALCL (pcALCL), anaplastic lymphoma kinase (ALK)-positive ALCL, and, provisionally, ALK-negative ALCL. Despite overlapping pathologic features, these tumors differ in clinical behavior and genetics. pcALCL presents in the skin and, while it may involve locoregional lymph nodes, rarely disseminates. Outcomes typically are excellent. ALK-positive ALCL and ALK-negative ALCL are systemic diseases. ALK-positive ALCLs consistently have chromosomal rearrangements involving the ALK gene with varied gene partners, and generally have a favorable prognosis. ALK-negative ALCLs lack ALK rearrangements and their genetic and clinical features are more variable. A subset of ALK-negative ALCLs has rearrangements in or near the DUSP22 gene and has a favorable prognosis similar to that of ALK-positive ALCL. DUSP22 rearrangements also are seen in a subset of pcALCLs. In this review, we discuss the clinical, morphologic, phenotypic, genetic, and biological features of ALCLs.
*Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
†Department of Pathology, Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
X.X. was supported by a scholarship award from the China Scholarship Council. A.L.F. currently is receiving grants from the National Cancer Institute (R01 CA177734) and the American Cancer Society (RSG-12-193-01-TBE), and is a Damon Runyon Clinical Investigator supported by the Damon Runyon Cancer Research Foundation (CI-48-09).
Presented in part at the Society for Hematopathology Companion Meeting held in conjunction with the 103rd Annual Meeting of the United States and Canadian Academy of Pathology, March 2, 2014, San Diego, CA.
The authors have no conflicts of interest to disclose.
Reprints: Andrew L. Feldman, MD, Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 (e-mail: email@example.com).
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