Introduction: The existence of a graft-versus-lymphoma effect is well established. When lacking a firm diagnosis, however, the clinician is challenged to to weigh the potential benefits of the graft-versus-lymphoma effect against potential dangers of graft-versus-host disease as well as against generalized (viral) infections.
Case presentation: We present evidence for a graft-versus-lymphoma effect in a 64-year-old caucasian woman with a transplanted peripheral blood-stem-cell graft from her Human Leukocyte Antigen-identical sister, and propose diagnostic measures to distinguish between graft-versus-host effect, and against viral disease or drug-induced reactions.
Conclusion: We were able to identify an allogeneic graft-reaction against progressive lymphoma alongside an erythema consistent with acute graft-versus-host disease of the skin. Establishing a firm diagnosis enabled us to decide against T-cell suppression (such as by using cyclosporine). Anti-lymphoma activity was favoured, by means of the allogeneic graft, local radiation and immunotherapy. This illustrates the importance of a sound differential diagnosis of erythema after allogeneic stem-cell transplantation, including assessment of viral disease of the affected tissue.