Bone Marrow, Acute myeloid leukemia with t(8;16) (KAT6A-CREBBP)

Acute myeloid leukemia (AML) is a clonal hematopoietic neoplasm due to acquired oncogenic mutations that disrupts differentiation, resulting in the accumulation of immature myeloid blasts in the marrow. The marrow replacement by blasts results in marrow failure and complications related to anemia, thrombocytopenia and neutropenia. AML can affect all ages, but the incidence increases throughout life.

This is a case of AML with monocytic differentiation and distinctive erythrophagocytosis, with history of previous chemotherapy for follicular lymphoma. Cytogenetic evaluation demonstrates t(8;16)(p11,p13) - a rare translocation resulting in a fusion between KAT6A (MYST3/MOZ) on chromosome 8 and CREBBP/CBP on chromosome 16. This translocation has been reported more frequently in therapy-related AML and is associated with poor prognosis, with a median overall survival of 8.5 months in all adult patients and six months in therapy-related AML. AML with t(8;16) may also be seen as de novo disease in infants, and is also associated with poor prognosis.

Of note the blast population was negative for the expression of CD34 and CD117, and positive for CD11c, CD33, CD38 (bright), CD36, CD64, CD56 (bright) and HLA-DR.

See Related Content for references:
1) Diab A, et al. Leuk Res. 2013 37(1):32-6.
2) Haferlach T, et al. Leukemia 2009. 23(5):934-43.