Objective:

To report a case of umbilical cord blood-derived early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a child with severe aplastic anemia.

Approach:

• Case Report: A 7-year-old girl with severe aplastic anemia underwent allo-HSCT using umbilical cord blood and developed ETP-ALL 2 years and 5 months post-transplant.

Key Findings:

• The patient developed ETP-ALL from umbilical cord blood donor cells after allo-HSCT.
• Despite multiple chemotherapy regimens, the patient did not achieve remission and ultimately died from the disease.
• The case illustrates the refractory nature of donor cell leukemia and indicates the need for further investigation into its biological mechanisms.

Interpretation:

The outcome illustrates the challenges in treating donor cell leukemia arising from umbilical cord blood, emphasizing the need for better understanding of its biological mechanisms.

Limitations:

• The rarity of donor cell leukemia limits the ability to generalize findings.
• The case study does not provide extensive data on the molecular mechanisms involved.

Conclusion:

The case underscores the serious implications of donor cell leukemia in pediatric patients post-transplant and the necessity for ongoing research.