title: Anaplastic lymphoma kinase-positive diffuse large B-cell lymphoma with a complex karyotype and cryptic 3' ALK gene insertion to chromosome 4 q22-24.
abstract: Anaplastic lymphoma kinase (ALK)-positive diffuse large B-cell lymphoma (DLBCL) is a rare tumor that is frequently associated with t(2;17)(p23;q23), a translocation fusing the ALK gene at 2p23 to the clathrin heavy chain gene (CLTC) at 17q23. Here, we report a unique case of ALK-positive DLBCL with plasmablastic morphology and focal cytoplasmic granular ALK stain in an HIV-negative 33-year-old man. By conventional karyotyping, the lymphoma cells were near-tetraploid and included 4 structurally normal copies each of chromosomes 2 and 17. Fluorescence in situ hybridization revealed an apparently normal, intact ALK gene on each of the 4 chromosome 2 homologs plus a cytogenetically cryptic ALK gene insertion into 2 of the 4 chromosome 4 homologs at band 4q22-24. The lymphoma cells expressed CD138, lambda light chain, focal and weak CD30, and exhibited aberrant T-cell antigens, including perforin. This case indicates that ALK-positive DLBCL is more heterogeneous at the cytogenetic/molecular level than previously recognized.
authors.affiliation: Department of Pathology, University of Massachusetts Medical Center, Worcester, MA 01605, USA.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Stachurski
authors.forename: Patricia Minehart
authors.initials: PM
authors.lastname: Miron
authors.forename: Samer
authors.initials: S
authors.lastname: Al-Homsi
authors.forename: Lloyd
authors.initials: L
authors.lastname: Hutchinson
authors.forename: Nancy Lee
authors.initials: NL
authors.lastname: Harris
authors.forename: Bruce
authors.initials: B
authors.lastname: Woda
authors.forename: Sa A
authors.initials: SA
authors.lastname: Wang
mesh_terms: D000328:Adult; D000077548:Anaplastic Lymphoma Kinase; D002869:Chromosome Aberrations; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D016393:Lymphoma, B-Cell / Q000235:genetics*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D020794:Receptor Protein-Tyrosine Kinases
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases