Figure 1. Patient 1: Excisional biopsy of the lymph node
involved by polymorphous Post-transplant lymphoproliferative disorder. A
- B. Histomorphologic findings of the lymph node biopsy reveal
effacement of the nodal architecture (A. 40x) by a mixed proliferation
of lymphocytes, immunoblasts, and plasma cells (B. 400x). C - F.
Immunohistochemical studies highlight mixed T-cells (C. CD3), B-cells
(D. PAX5), and polytypic plasma cells (E. CD138, F. Kappa, G Lambda).
EBV EBER in-situ hybridization (H) highlights scattered EBV-positive
cells.
Clonal B-cell rearrangement was demonstrated by the presence of a
discrete peak following PCR with primers specific for the JH
immunoglobulin heavy chain locus. In addition, PCR revealed prominent
polyclonal background.
Concurrent bone marrow biopsy demonstrated normocellular marrow for age
with infiltration of abnormal lambda light chain-restricted plasma cells
(6% of all cells), small B-lymphocytes (18% of all cells), and T-cells
(12% of all cells) consistent with marrow involvement by the PTLD,
involving about 30% of all marrow (Figure 2 ). Histologic
findings in the bone marrow resemble the lymph node. Cytogenetic
studies, performed on the bone marrow aspirate, showed an abnormal
female chromosome analysis comprised of two clones. 108