title: Leukemias resembling acute promyelocytic leukemia, microgranular variant.
abstract: Acute promyelocytic leukemia (APL) should be distinguished from other subtypes of acute myeloid leukemia (AML) because of the increased risk of disseminated intravascular coagulation (DIC) and its response to arsenic compounds and retinoids. Some cases of AML seem morphologically similar to the microgranular variant of APL (French-American-British [FAB] AML-M3v) but lack the t(15;17). We evaluated 8 cases of APL-like leukemias for subtle morphologic, cytochemical, immunophenotypic, and cytogenetic differences compared with 5 cases of promyelocytic leukemia/retinoic receptor alpha (PML/RARalpha)-positive APL (FAB AML-M3v). We also evaluated both groups for the presence of DIC. No differences among the groups were noted in blast size, chromatin pattern, nuclear morphologic features, intensity of myeloperoxidase staining, or presence of Auer rods. Immunophenotypes were similar; both types of cases lacked CD34 and HLA-DR and were CD13+ and CD33+. Two cases of APL-like leukemias also were CD56+. DIC was present in 2 patients with M3v. Our study shows that there are no definitive morphologic, cytochemical, or immunophenotypic findings that can distinguish these cases from PML/RARalpha-positive APL.
authors.affiliation: Department of Pathology, University of Iowa College of Medicine, Iowa City, USA.
authors.forename: Sanjai
authors.initials: S
authors.lastname: Nagendra
authors.forename: Howard
authors.initials: H
authors.lastname: Meyerson
authors.forename: Glenda
authors.initials: G
authors.lastname: Skallerud
authors.forename: Nancy
authors.initials: N
authors.lastname: Rosenthal
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D018826:CD13 Antigens / Q000032:analysis; D019002:CD56 Antigen / Q000032:analysis; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D020732:Cytogenetic Analysis; D003937:Diagnosis, Differential; D004211:Disseminated Intravascular Coagulation; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D016130:Immunophenotyping; D007621:Karyotyping; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000473:pathology; D015473:Leukemia, Promyelocytic, Acute / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D018168:Receptors, Retinoic Acid / Q000032:analysis; D000072482:Retinoic Acid Receptor alpha; D063268:Sialic Acid Binding Ig-like Lectin 3; D014178:Translocation, Genetic
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D015214:Antigens, Differentiation, Myelomonocytic; C571163:CD33 protein, human; D019002:CD56 Antigen; D006684:HLA-DR Antigens; C000607071:RARA protein, human; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D063268:Sialic Acid Binding Ig-like Lectin 3; D018826:CD13 Antigens