Table 1.
Characteristic features of consultation cases representing AITL, PTCLU and ALK (−) ALCL
| AITL | PTCLU | ALK (−) ALCL | |
|---|---|---|---|
| TOTAL CASES | 80 | 14 | 10 |
| AGE | 65 | 61 | 60 |
| SEX | 40F / 40M | 11 M / 3 F | 6 M / 4 F |
| T-CELL CLONE DETECTED | 24 / 43 | 5 / 6 | 1 / 1 |
| 56% | 83% | 100% | |
| B-CELL CLONE DETECTED | 11 / 30 | 2 / 3 | N.D. |
| 37% | 67% | N/A | |
| EBV POSITIVE BY ISH | 46 / 72 | 2 / 11 | 1 / 5 |
| 64% | 18% | 20% | |
| LARGE B-CELL PROLIFERATION | 34 / 80 | 1 / 14 | 0 / 10 |
| 43% | 7% | 0% | |
| EXPANDED FDCS | 66 / 70 | 0/14 | N.D. |
| 94% | 0% | N/A | |
| CXCL13 | 68 / 76 | 1 / 4 | 0 / 2 |
| 89% | 25% | 0% | |
| PD-1 | 74 / 80 | 10 /14 | 2 / 10 |
| 93% | 71% | 20% | |
Abbreviations: AITL – angioimmunoblastic T-cell lymphoma; PTCLU – peripheral T-cell lymphoma, unclassified; ALCL – anaplastic large cell lymphoma; ISH – in-situ hybridization; FDCS – follicular dendritic cells. In-situ hybridization for the presence of EBV was performed as described in the materials and methods section. Presence of a large B-cell proliferation was determined by a combination of immunohistochemistry, detection of EBV RNA by in situ hybridization in large cells and the presence of a B-cell clone by molecular methods.12,13 Only 7 of 34 instances where AITL was complicated by a large B-cell proliferation lacked detectable EBV within neoplastic cells by in-situ hybridization. Expanded FDCs refer to the presence of expanded follicular dendritic cell networks as detected by CD21 immunohistochemistry.