Appearance of del(11q) in two patients with acute promyelocytic leukaemia treated with all-trans retinoic acid and combination chemotherapy

Two acute promyelocytic leukaemia patients, treated with all-trans retinoic acid and combination chemotherapy, acquired a deletion of 11q within 12 months of diagnosis. One patient died in relapse, with both t(15;17) and del(11q) cell lines co-existing. Patient 2 remains in remission with del(11q) in 70% metaphases, despite normal marrow morphology. No deletion of the MLL gene was identified in the latter patient. The early appearance of a del(11q) is unusual, particularly without morphological evidence of myelodysplasia. We hypothesize that the del(11q) was therapy-induced but the absence of other genetic lesions has resulted in no accompanying morphological changes.