| PTLD Classification of 1997 (Harris
et al.) |
| Category |
Examples |
Histopathology |
Clonal Status |
Oncogene, Tumor Suppressor Gene Changes |
Comments |
| "Early" lesions |
Reactive plasmacytic hyperplasia, (atypical lymphoid hyperplasia)*, infectious mononucleosis-like |
Some architectural preservation; numerous plasma cells and lymphocytes; many immunoblasts may be present; atypia slight |
Polyclonal; Minor clones may be present |
(None) |
Often regress with reduced immunosuppression, severe cases may be fatal |
| PTLD-Polymorphic |
(Polymorphic B cell hyperplasia)*, (Polymorphic B cell lymphoma)*, (Polymorphic PTLD)* |
Destruction of underlying architecture, full range of B-cell maturation seen, may have necrosis, scattered large bizarre cells (atypical immunoblasts), frequent mitoses, may have monomorphic areas |
Monoclonal; Rare cases may be
polyclonal |
None |
Overall impression of mixed small and large cell lymphoma or polymorphous immunocytoma; may be multiple; Some cases regress with reduced immunosuppression, others may progress |
| PTLD- Monomorphic |
B-cell lymphomas: Diffuse large B-cell lymphoma (e.g., immunoblastic, centroblastic, anaplastic subtypes), Burkitt's or Burkitt-like lymphoma
T-cell lymphomas: Peripheral T-cell
lymphoma, unspecificed type (usu. large cell), Anaplastic large cell lymphoma (T or null cell), Other types (eg, T-NK) |
Majority of cells are transformed with cytologic atypia, prominent nucleoli, basophilic cytoplasm, underlying architectural effacement/destruction |
Monoclonal |
Present in some cases |
Recommended that these be classified according to standard lymphoma classification, with term " PTLD" added; Monomorphism means that most cells are transformed- cellular monotony may be present but is not required; T cell antigens CD43
and CD45RO
may be present on B cells in these cases; Some B cell tumors may regress with reduced immunosuppression; T cell PTLD had longer time to onset and did not regress in this sample. |
| PTLD-Other |
a) T-cell rich/Hodgkin's disease-like B-PTLD, b) Plasmacytoma-like PTLD |
a) Diffuse background of small lymphocytes with scattered Reed-Sternberg-like cells; b) diffuse infiltrate of mature plasma cells |
Monoclonal |
None described |
T cell-rich/HD-like B-PTLD may regress with reduced immunosuppression |
|
*Cases included in classification but examples not presented for review at Society
for Hematopathology Workshop
|
