title: CLTC-ALK fusion as a primary event in congenital blastic plasmacytoid dendritic cell neoplasm.
abstract: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a subtype of acute myeloid leukemia, affecting mainly the elderly. It is thought to be derived from plasmacytoid dendritic cell precursors, which frequently present as cutaneous lesions. We have made a detailed analysis of an infant with BPDCN, who manifested with hemophagocytic lymphohistiocytosis. The peripheral blood leukocytes revealed the t(2;17;8)(p23;q23;p23) translocation and a CLTC-ALK fusion gene, which have never been reported in BPDCN or in any myeloid malignancies thus far. Neonatal blood spots on the patient's Guthrie card were analyzed for the presence of the CLTC-ALK fusion gene, identifying the in utero origin of the leukemic cell. Although the leukemic cells were positive for CD4, CD56, CD123, and CD303, indicating a plasmacytoid dendritic cell phenotype, detailed analysis of the lineage distribution of CLTC-ALK revealed that part of monocytes, neutrophils, and T cells possessed the fusion gene and were involved in the leukemic clone. These results indicated that leukemic cells with CLTC-ALK originated in a multipotent hematopoietic progenitor in utero. This is the first report of the CLTC-ALK fusion gene being associated with a myeloid malignancy, which may give us an important clue to the origin of this rare neoplasm.
authors.affiliation: Department of Pediatrics, Ehime University Graduate School of Medicine, Toon, Ehime, Japan.
authors.forename: Kiriko
authors.initials: K
authors.lastname: Tokuda
authors.forename: Minenori
authors.initials: M
authors.lastname: Eguchi-Ishimae
authors.forename: Chihiro
authors.initials: C
authors.lastname: Yagi
authors.forename: Mika
authors.initials: M
authors.lastname: Kawabe
authors.forename: Kyoko
authors.initials: K
authors.lastname: Moritani
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Niiya
authors.forename: Hisamichi
authors.initials: H
authors.lastname: Tauchi
authors.forename: Eiichi
authors.initials: E
authors.lastname: Ishii
authors.forename: Mariko
authors.initials: M
authors.lastname: Eguchi
mesh_terms: D002889:Chromosomes, Human, Pair 2 / Q000235:genetics; D003713:Dendritic Cells / Q000473:pathology*; D005260:Female; D050939:Gene Fusion; D006801:Humans; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000151:congenital / Q000235:genetics* / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics*
chemical_list: D015514:Oncogene Proteins, Fusion; C408996:oncoprotein CLTCL-ALK