Relapsed acute myelogenous leukemia occurring after 18 years with recurrent novel chromosomal abnormality t(18;22)(q23;q11.2)

A 22-year-old woman presented with lymphadenopathy in a similar manner as she had presented at age 4. At age 4, she was diagnosed with acute myelogenous leukemia (AML) with t(18;22)(q23;q11.2) and received chemotherapy until age 6 under a pediatric study protocol. At age 22, a lymph node biopsy confirmed granulocytic sarcoma, and a bone marrow aspirate showed increased myeloblasts with no dysplasia. Cytogenetic analyses of the lymph node and the bone marrow were positive for t(18;22)(q23;q11.2). The patient was treated for relapsed AML and at writing had been disease-free for 9 months. Translocation between chromosomes 18 and 22 has been reported in indolent lymphoproliferative disorders, but not in AML. Although we do not know the precise molecular etiology of this leukemia, the uncommon presentation for AML and late relapse with the same chromosomal abnormality may indicate a causal relationship between this novel chromosomal abnormality and the AML. This observation also suggests the possible presence of dormant stem cells containing the chromosomal abnormality in this particular patient.