Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation offers patients the only prospect of long-term survival for a substantial variety of otherwise incurable malignant neoplasms as well as selected non-neoplastic conditions. This therapeutic modality, however, carries significant risks and is associated with a wide range of complications affecting not only the bone marrow but many organ systems, in particular by graft-versus-host disease. Patients before, during, and following stem cell transplantation thus require close monitoring and the pathologist is frequently implicated in this process. The aim of this chapter is to provide the pathologist with the tools required to interpret biopsies from these patients at all stages of the transplantation process. Following an overview of hematopoietic stem cell transplantation and graft-versus-host disease, the chapter will focus on the histopathologic findings of graft-versus-host disease and other complications in several organs and tissue including bone marrow, skin, lung, kidney, gastrointestinal tract and liver, with emphasis on the diagnostic criteria and approaches to graft-versus-host disease.