Pathological findings of ATLL with HTLV-1–infected HRS-like cells: immunophenotype, background cell characteristics, and molecular findings
| . | Immunophenotype of HRS-like cells . | Characteristics of background cells . | Molecular findings . | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Case . | TIA-1 . | Fascin . | CCR4 . | MUM1 . | HBZ-ISH . | EBER . | T-cell component . | Eosinophils . | Abnormal T-phenotype* . | Ki-67 index, % . | TCRG . | IGH . | HTLV-1 SBH . |
| 1 | − | + | − | + | + | −† | CD4 > CD8 | − | − | 32 | Polyclonal | Polyclonal | − |
| 2 | − | − | − | + | + | −† | CD4 = CD8 | + | − | 38 | Polyclonal | Polyclonal | ND |
| 3 | − | − | − | + | + | −† | CD4 > CD8 | − | − | 24 | Polyclonal | Polyclonal | − |
| 4 | − | + | − | + | + | −† | CD4 (monotonous) | − | + | 26 | Clonal | Polyclonal | + |
| 5 | − | + | − | + | + | −† | CD4 > CD8 | − | − | 30 | NE | Polyclonal | ND |
| 6 | − | + | − | + | + | −† | CD4 > CD8 | + | − | 22 | NE | NE | +/−‡ |
| 7 | − | + | − | + | + | −† | CD4 = CD8 | + | − | 43 | Clonal§ | Polyclonal | +/−‡ |
| 8 | − | + | + | + | + | −† | CD4 = CD8 | + | − | 35 | Clonal§ | Polyclonal | ND |
| . | Immunophenotype of HRS-like cells . | Characteristics of background cells . | Molecular findings . | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Case . | TIA-1 . | Fascin . | CCR4 . | MUM1 . | HBZ-ISH . | EBER . | T-cell component . | Eosinophils . | Abnormal T-phenotype* . | Ki-67 index, % . | TCRG . | IGH . | HTLV-1 SBH . |
| 1 | − | + | − | + | + | −† | CD4 > CD8 | − | − | 32 | Polyclonal | Polyclonal | − |
| 2 | − | − | − | + | + | −† | CD4 = CD8 | + | − | 38 | Polyclonal | Polyclonal | ND |
| 3 | − | − | − | + | + | −† | CD4 > CD8 | − | − | 24 | Polyclonal | Polyclonal | − |
| 4 | − | + | − | + | + | −† | CD4 (monotonous) | − | + | 26 | Clonal | Polyclonal | + |
| 5 | − | + | − | + | + | −† | CD4 > CD8 | − | − | 30 | NE | Polyclonal | ND |
| 6 | − | + | − | + | + | −† | CD4 > CD8 | + | − | 22 | NE | NE | +/−‡ |
| 7 | − | + | − | + | + | −† | CD4 = CD8 | + | − | 43 | Clonal§ | Polyclonal | +/−‡ |
| 8 | − | + | + | + | + | −† | CD4 = CD8 | + | − | 35 | Clonal§ | Polyclonal | ND |
HBZ-ISH, RNAscope for HTLV-1 bZIP factor; MIB-1 LI, MIB-1 labeling index; NE, not evaluable; ND, not done; SBH, Southern blot hybridization; TCRG, TCR-γ chain gene.
At least one of the pan-T-cell markers deletions, including CD2, CD3, CD5, and CD7, recognized by immunohistochemistry and/or flow cytometry.
Few positive cells were observed in all cases, but positive cells were small to medium-sized, and HRS-like cells were negative.
Very faint bands were identified.
Monoclonal peak was identified with polyclonal backgrounds.