title: HLA-DR antigen-positive acute promyelocytic leukemia.
abstract: Acute promyelocytic leukemia (APL) with t(15;17)(q22;q21)/PML-RARα is a subtype of acute myeloid leukemia (AML) with distinct morphologic and immunophenotypic characteristics. It is a highly aggressive disease that requires rapid diagnosis and early intervention. In addition to morphologic evaluation, flow cytometry has been widely used to facilitate prompt diagnosis of this disease. Compared with other types of AML, APL typically displays a triad of absent or weak CD34, absent HLA-DR, and positive CD117. HLA-DR positive APL is extremely rare and its clinical and pathological features have not been reported. A total of 45 cases of APL with t(15,17)/PML-RARα were diagnosed at Harbor-UCLA Medical Center from year 2006 to 2015. Among them, only two cases were positive for HLA-DR by flow cytometry immunophenotyping. Here we describe the clinical, morphologic, immunophenotypic, and cytogenetic features of these two cases.
authors.affiliation: Department of Pathology, Harbor-UCLA Medical Center, 1000 West Carson Street, Torrance, CA 90502, USA.
authors.forename: Alejandro S
authors.initials: AS
authors.lastname: Mendoza
authors.affiliation: Department of Pathology, Harbor-UCLA Medical Center, 1000 West Carson Street, Torrance, CA 90502, USA. Electronic address: drqingx@yahoo.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Qing
authors.affiliation: Department of Hematology and Oncology, Harbor-UCLA Medical Center, 1000 West Carson Street, Torrance, CA 90502, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Dungo
authors.affiliation: Department of Pediatrics, Harbor-UCLA Medical Center, 1000 West Carson Street, Torrance, CA 90502, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Lasky
authors.affiliation: Department of Pediatrics, Harbor-UCLA Medical Center, 1000 West Carson Street, Torrance, CA 90502, USA.
authors.forename: Eduard
authors.initials: E
authors.lastname: Panosyan
authors.affiliation: Terasaki Research Institute, Los Angeles, CA, USA. Electronic address: cai@terasakilab.org.
authors.forename: Junchao
authors.initials: J
authors.lastname: Cai
mesh_terms: D001752:Blast Crisis / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D015473:Leukemia, Promyelocytic, Acute / Q000097:blood / Q000276:immunology*; D008875:Middle Aged; D055815:Young Adult
chemical_list: D006684:HLA-DR Antigens
keywords: Acute promyelocytic leukemia; Flow cytometry; HLA-DR; Prognosis