[All-trans retinoic acid was effective for marked skin infiltration in a relapsed acute myelogenous leukemia (AML-M2) patient with t(12; 17)].

A 64-year-old man who had taken acute myelogenous leukemia (AML-M2) in 1989 have relapsed with t(12; 17) (p13; q11.2-21) chromosomal abnormality and presenting marked infiltration to the skin in 1994. Blasts were seen on his peripheral blood smear (15%) and bone marrow examination showed increased leukemic cells (56%), with maturation. Leukemic cells expressed CD13 and CD33 antigen but not HLA-DR. Although leukemic cells had not promyelocytic feature morphologically, detection of PML/RAR alpha infusion signal of peripheral leukemic cells were positive for 8% (1% for control) by fluorescence in situ hybridization method. Because he did not response to standard combination chemotherapy and because we considered the possibility that t(12; 17) (p13; q11.2-21) observed in this case are t(15; 17) variant, we tried all trans retinoic acid (ATRA) to him. Interestingly, ATRA was very effective for skin lesion but hematologically it had no effect at all, and he died because of bacterial pneumonia.