Leukaemic relapse of donor origin after allogeneic bone marrow transplantation from a donor who later developed bronchogenic carcinoma

Donor- derived leukaemia is exceptional after allogeneic bone marrow transplantation ( BMT). A woman with chronic myeloid leukaemia received an allogeneic BMT from a human leucocyte antigen- identical brother. The donor, a 50- year- old non- smoker, died of squamous cell bronchogenic carcinoma 1 year later. At 4 years post BMT, the patient became BCR/ ABL positive and relapsed with acute myeloid leukaemia, which was shown to be donor- derived cytogenetically and molecularly. Retrospective analysis showed that the donor- leukaemic clone had started to evolve as early as 6 months post BMT. Sequencing of p53 ruled out Li - Fraumeni syndrome. Predisposition to malignancy might be an underlying mechanism of donor- cell leukaemia.