HDCN Article Review/Hyperlink

Anderson L, Papadimetriou JC, Kuo PC, Johnson LB, Klassen DK, Hoehn-Saric E, Weir MR, Bartlett ST

Histopathology of renal posttransplant lymphoproliferation: comparison with rejection using the Banff Schema

Am J Kidney Dis (Oct) 28:578-584 1996

One of the more difficult and more important distinctions to be made in evaluating the histopathology of renal transplant biopsies is the differentiation between severe acute rejection and post transplant lymphoproliferative disease. Part of the difficulty arises from the fact that both entities can be present simultaneously. It is just this specific problem that has been addressed in this study from the extensive transplant experience at the University of Pittsburgh.

The authors were able to compare nine examples of PTLD documented by Epstein-Barr virus in situ hybridization and analysis of B cell lineage with nine allograft nephrectomies classified as severe acute rejection using the Banff Schema. The authors focus on those features which can be considered to be characteristic of PTLD rather than on the absence of features characteristic of rejection.

PTLD as a neoplastic or pre-neoplastic process is characterized by features which are typical of lymphomas, namely space occupying expansile infiltrates which push apart the tubular architecture rather than invading the parenchyma and the presence of nuclear atypia in the pleomorphic lymphocytic infiltrate. Another feature which the authors bring to attention is something which they term serpiginous necrosis which is essentially foci of central necrosis within the expansile nodules of neoplastic tissue. This is a feature which in my personal experience has not been prominent in needle biopsies as is suggested by this report where it was seen in nine out of nine cases of PTLD. It is also of interest that some degree of tubulitis was also identified in all of the patients with PTLD, suggesting the possibility of either a concurrence of rejection and the lymphoproliferative process or, as the authors hypothesize, a reflection of the infiltrative potential of the PTLD cells.

Comment: The study is of importance in highlighting those features of PTLD which can be evaluated early in needle biopsy specimens to raise the suspicion of the presence of PTLD pending confirmatory results of immunophenotyping and in situ hybridization. (Michael Kashgarian MD, Yale University)