A case of high-risk AML in a patient with advanced systemic mastocytosis

Abstract

Aggressive SM + AML has limited therapeutic options. Even a strong combination of decitabine-venetoclax-midostaurin has a transient effect on AML and a mitigated effect on SM. Larger series are required to identify the best therapeutic strategy.

Keywords: HAM regimen; advanced systemic mastocytosis (AdvSM); cladribine; concurrent hematologic disease; decitabine–venetoclax (DEC‐VEN); refractory acute myeloid leukemia (R‐AML).

FIGURE 1

Immunohistochemical features of SM‐AHN (A–F). Photomicrograph of the bone marrow histology and immunohistochemistry supporting the diagnosis of SM‐AHN. SM and MDS/MPN: hypercellularity, granulocytic lineage expansion and paratrabecular infiltration of mast cells (MCs) (arrow) with the characteristic delicate fibrosis (arrowed), hematoxylin and eosin (H&E) stain (A); paratrabecular infiltration of MCs. The mast cell granules are well highlighted by the metachromatic staining with toluidine blue (B); cellularity predominantly determined by granulopoiesis expressing CD15 (C); positive immunostaining (brown) of spindle‐shaped MCs with CD 117 (D), CD25 (E), and tryptase (F). Morphology (G–I). AML: blasts and neutrophils (leukemic hiatus) (G, H). This PB smear was made after the first cycle of venetoclax and shows blast clearance with the persistence of pathologic spindle‐shaped MCs (in the picture) (I).

FIGURE 2

Graphs representing the trend of white blood cell count (A), platelet count (B), and tryptase level (C) from SM‐AHN diagnosis in 2017 until exitus in 2021. The graphs reflect the patient's measured platelet count (PLT), white blood cell count (WBC), and tryptase level after treatment with HU and H1/H2 antagonists, MDS/MPN evolution to AML and SM‐AML I and II line therapies. AML, acute myeloid leukemia; C, cycle; DEC, decitabine; D, day; GCSF, granulocyte colony‐stimulating factor; HU, hydroxyurea; MID, midostaurine; MLFS, morphologic leukemia‐free state; SM‐AHN, systemic mastocytosis with associated hematologic neoplasm; VEN, venetoclax.