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, λ 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.
Original language | English (US) |
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Pages (from-to) | 940-945 |
Number of pages | 6 |
Journal | Human Pathology |
Volume | 38 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2007 |
Externally published | Yes |
Keywords
- 4q22-24
- ALK
- Cytogenetics
- Diffuse large B-cell lymphoma
- Fluorescence in situ hybridization (FISH)
ASJC Scopus subject areas
- Pathology and Forensic Medicine