Cytomegalovirus (CMV) pneumonia is an important cause of treatment related mortality after allogeneic stem cell transplantation (SCT) and autologous SCT, particularly in a CD34 selected setting. There is little known about the immune reconstitution pertaining to the CMV after CD34 selected SCT. However, several studies have suggested there is more profound immunodeficiency early in the CD34 selected population compared with the unselected population. We encountered two fatal cases of CMV pneumonia at the CD34 selected SCT for T-cell lymphoblastic lymphoma and high-risk breast cancer that was confirmed through a lung biopsy and bronchoalveolar lavage. In conclusion, autologous CD34 selected CMV seropositive recipients need to be monitored in a similar manner to allogeneic recipients.

Keywords: CMV pneumonia, CD34 selected stem cell transplantation, T-cell lymphoblastic lymphoma, Breast cancer