Table 1 Pathologic Features of EBVMCU
| Histology | Immunophenotype |
|---|---|
| Shallow, sharply circumscribed ulcers |
Immunoblasts often with HRS features: strong positivity for CD10, CD30, MUM1 uniform positivity for PAX5 and OCT-2 variable expression of CD20, CD45, CD15, CD79a, BCL-6, BOB.1 |
| Localized to mucosa of oropharynx and gastrointestinal tract or to skin |
Infiltrating lymphocytes: CD4 and CD8 positivity |
| Polymorphous infiltrate of lymphocytes and immunoblasts | Clonality |
| Variable admixture of scattered plasma cells, eosinophils, and histiocytes |
Immunoblasts with HRS features: monoclonal immunoglobulin rearrangement |
| Medium sized lymphocytes with angulated nuclei |
Infiltrating T-lymphocytes: frequent monoclonal or restricted TCR pattern |
| Pleomorphic immunoblasts with frequent Hodgkin and Reed-Sternberg (HRS) morphology | Association with EBV |
| Plasmacytoid apoptotic cells |
Immunoblasts and HRS cells: uniformly EBER1-positive |
| Variable angioinvasion |
Infiltrating T-lymphocytes: frequently EBER1-positive |
| Variable tissue necrosis |
Plasmacytoid apoptotic cells: uniformly EBER1-postive |