Donor Cell-Derived Myelodysplastic Syndrome Following Allogenic Peripheral Blood Stem Cell Transplant.

Donor cell-derived leukemia is a rare but well-described complication of allogeneic hematopoietic stem cell transplant (HSCT). This clinical case report aims to highlight the importance of recognizing this unusual disorder and thus, ensuring its appropriate management. We herein describe a case of a 9-year-old male diagnosed with acute lymphoblastic leukemia (ALL) and relapsed after initial chemotherapy. Subsequently, the patient had an allogenic peripheral blood stem cell transplant (PBSCT) from an HLA-matched, unrelated donor. Unfortunately, the patient then developed progressive thrombocytopenia, and following investigation, including bone marrow examination and cytogenetic analysis, he was diagnosed with donor cell-derived myelodysplastic syndrome. The literature review emphasizes the importance of considering it as a differential diagnosis of disease relapse following allogeneic HSCT.