1) Early lesions – architectural preservation of the involved tissue, polyclonal nature, younger pts, and usual regression with withdrawal of immunosupression.

a) Infectious mononucleosis

b) Plasmacytic hyperplasia

2) PTLD Polymorphic – full range of B-cell maturation displayed, with effacement of tissue architecture and variable response to altered degree of immunosupression.

        a) Polyclonal (rare)

        b) Monoclonal (common)

3) PTLD, monomorphic (also classified as lymphomas) – overt monoclonal malignant lymphomas of B or T cell lineage, diagnosed by architectural and cytologic atypia, and clinical correlation. 

4) Hodgkin lymphoma and Hodgkin lymphoma-like PTLD – seen in allogenic bone marrow transplantation