A rare case of systemic mastocytosis with t(8;21) acute myeloid leukaemia in a young girl: a case report

Mastocytosis is a rare disorder due to the abnormal proliferation of clonal mast cells. Mast cells exist in most tissues, mature in situ from hematopoietic stem cells and develop unique characteristics of local effector cells. It manifests as two main categories: cutaneous mastocytosis and systemic mastocytosis (SM). Patients presenting with SM-acute myeloid leukaemia (AML) often have the worst outcome. Here we present a patient with the simultaneous diagnosis of SM associated with t (8;21) (q22;q22) acute myeloid leukaemia, M2 subtype in the French-American-British (FAB) classification, carrying a population of immature mast cell precursors. Initially, she was diagnosed with AML with t (8;21) (q22;q22) and was started on increase in blast cells. However, abnormal mast cells were seen distributed throughout the marrow spaces, which expressed mast cell tryptase, CD117 and CD68. She was then diagnosed as SM associated with t(8;21) to death due to severe neutropenic sepsis postin diagnosis.