Acute monoblastic leukemia as the rare presentation of AML with Myelodysplasia Related Changes (MRC)

Abstract

In 2008, the revised World Health Organization (WHO) classification of hematopoietic neoplasms introduced a new entity as a subcategory in the classification of acute myeloid leukemias (AML) entitled “acute leukemia with myelodysplasia-related changes” (AML-MRC) replacing the previously suggested entity in the 2001 classification “acute myeloid leukemia with multilineage dysplasia” (AML-MLD). Morphologic evaluation of dyspoiesis can be unreliable when there are very few residual hematopoietic cells and the blast count is high.Unlike the AML-MLD category, which relied mainly on morphology; this new AML-MRC category provides ample criteria for diagnosis, including cytogenetics. Acute myeloid leukemia with myelodysplasia related changes having unbalanced chromosomal abnormalities like 7q deletion are aggressive leukemias with a poor prognosis. We report one such rare case of acute myeloid leukemia presenting with extramedullary involvement and gingival swelling, morphologically and clinically resembling acute monoblastic leukemia but associated with 7q deletion.