Post-transplant lymphoproliferative disorder, polymorphous type. Lymph node sections. (A) Replacement by a mixture of small lymphocytes, larger (activated) lymphocytes, and plasma cells. (B) In situ hybridization indicates expression of Epstein-Barr virus–associated early RNA (EBER). Black nuclear staining represents positive reaction in a significant subset of cells. Flow cytometry studies on the same sample showed a mixed population of B cells and plasma cells. In situ hybridization for kappa and lambda light chain expression confirmed that plasma cells were polyclonal (not shown). This lesion represents a lymph node from a patient who had had a liver transplant and had elevated serum Epstein-Barr virus copy numbers.
Post-transplant lymphoproliferative disorder, high grade. (A) Shows the H&E histologic appearance with cells that would be classified as large B-cell lymphoma. (B) Scattered cells are positive for Epstein Barr virus latent early RNA (EBER) by in situ hybridization. The brown reaction product in nuclei indicate a positive staining reaction. This case in a renal transplant patient would be classified as an Epstein Barr virus–positive large B-cell lymphoma, occurring in a post-transplant setting. In settings where post-transplant lymphoproliferative disorders are clonal, meeting the central criterion for a diagnosis of lymphoma, the morphologic and immunophenotypic data is used to subclassify the lymphoma according to the World Health Organization classification of hematological malignancy.