Acute Myeloid Leukemia with Occult Systemic Mastocytosis or Atypical Mast Cells Post-induction

Abstract

Systemic mastocytosis (SM) is a state of disease that is related to the clonal, neoplastic proliferation of mast cells. Patients who present with SM-Acute Myeloid Leukemia (AML) often have the worst outcome. We present a case of an 18-year-old female who was diagnosed with AML (FLT3 (Fms like tyrosine kinase 3) and PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha) translocation-negative) and after initial treatment with a standard induction regimen of cytarabine and daunorubicin (3+7 regimen), her bone marrow showed blast cells less than 5% and dense aggregates/sheets of atypical/immature mast cells with immunohistochemical stain CD117+ve and toluidine blue positive in mast cell aggregates. Mastocytosis is a clonal neoplastic proliferation of mast cells that accumulate in one or more organ system. Therefore, it is essential to diagnose systemic mastocytosis, particularly in patients of hematological neoplasms.

Systemic mastocytosis associated with acute myeloid leukaemia

“…In a few articles, a case with a similar appearance to ours was recorded, in which the physicians only detected the presence of SM in AML after a few chemotherapy cycles. 5,6,7 It is possible that the component of the non-mast cell lineage does not exhibit the same c-kit mutation as neoplastic mast cells. Two explanations for the pathogenesis of SM associated with myeloid neoplasm have been proposed: an acquired c-kit mutation that transformed a myeloid stem cell and an activating c-kit mutation that developed in conjunction with other genetic changes and events in a myeloid stem cell.…”