title: Langerhans cell histiocytosis in acute leukemias of ambiguous or myeloid lineage in adult patients: support for a possible clonal relationship.
abstract: Four patients presented with acute leukemia of ambiguous or myeloid lineage in association with Langerhans cell histiocytosis and provide evidence suggesting a common origin of the two neoplasms. One patient had a non-constitutional trisomy 21 in both the leukemic blasts and the Langerhans cells indicative of a clonal relationship. A second case expressed CD2, CD13, and CD117 on both the Langerhans cells and the blasts suggesting a possible clonal relationship. All four cases exhibited geographic intermingling of the Langerhans cell histiocytosis and acute leukemia and shared unique features including extramedullary leukemia involving lymph nodes in all cases with Langerhans cell histiocytosis only present in sites involved by acute leukemia. T-cell antigen expression was present in all cases with one meeting criteria for mixed phenotype acute leukemia, T/myeloid, not otherwise specified. These findings support the concept that coexistent Langerhans cell histiocytosis and acute leukemia is clonally related in some cases. Furthermore, these cases of acute myeloid or acute leukemia of ambiguous lineage with Langerhans cell histiocytosis share some unique features suggesting a common underlying neoplastic hematopoietic stem cell.
authors.affiliation: Special Hematology Laboratory, Division of Hematopathology, University of Minnesota Medical Center, Fairview, Minneapolis, MN, USA.
authors.forename: Sophia L
authors.initials: SL
authors.lastname: Yohe
authors.affiliation: ProPath, Dallas, TX, USA.
authors.forename: Carrie B
authors.initials: CB
authors.lastname: Chenault
authors.affiliation: Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
authors.forename: Emina E
authors.initials: EE
authors.lastname: Torlakovic
authors.affiliation: Division of Hematopathology, Miraca Life Sciences, Phoenix, AZ, USA.
authors.forename: Sheryl L
authors.initials: SL
authors.lastname: Asplund
authors.affiliation: Special Hematology Laboratory, Division of Hematopathology, University of Minnesota Medical Center, Fairview, Minneapolis, MN, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: McKenna
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications / Q000235:genetics / Q000473:pathology*; D006801:Humans; D007938:Leukemia / Q000150:complications / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000473:pathology