Differential Diagnosis of PBL
| . | PBL . | Common DLBCL . | Plasmacytoma . | BL . |
|---|---|---|---|---|
| Size of the tumor cell | Large | Large | Intermediate | Intermediate |
| Plasmablastic differentiation4-150 | + | − to −/+ | −/+ | − |
| CD20 (L26) | − to −/+ | + | − | + |
| CD45 (LC) | − to −/+ | + | − | + |
| CD79a (JCB117) | − to + | + | +50% | + |
| VS38c | + | − to −/+ | + | − |
| Ki-67 (MIB-1) | PI > 90% | PI: 30% to 90% | PI: 5% to 60% | PI > 95% |
| Ig heavy chain | G | G, M, and/or D | G, A, M, or D | M |
| BCL-2 (124) | − to + | − to + | − to + | − |
| BCL-6 (PG-B6P) | − to −/+ | +50% | Not known | +100% |
| . | PBL . | Common DLBCL . | Plasmacytoma . | BL . |
|---|---|---|---|---|
| Size of the tumor cell | Large | Large | Intermediate | Intermediate |
| Plasmablastic differentiation4-150 | + | − to −/+ | −/+ | − |
| CD20 (L26) | − to −/+ | + | − | + |
| CD45 (LC) | − to −/+ | + | − | + |
| CD79a (JCB117) | − to + | + | +50% | + |
| VS38c | + | − to −/+ | + | − |
| Ki-67 (MIB-1) | PI > 90% | PI: 30% to 90% | PI: 5% to 60% | PI > 95% |
| Ig heavy chain | G | G, M, and/or D | G, A, M, or D | M |
| BCL-2 (124) | − to + | − to + | − to + | − |
| BCL-6 (PG-B6P) | − to −/+ | +50% | Not known | +100% |
Abbreviations: +, expression of the antigen in the majority of cells, percentage of positive cases in a given subgroup of tumors; −, absence of antigen expression; −/+, weak antigen expression; BL, Burkitt's lymphoma; PI, proliferation index; DLBCL, diffuse large B-cell lymphoma.
Abundant deeply basophilic cytoplasm with a paranuclear hof and large chromatin-poor nuclei containing prominent nucleoli.