Analysis of microdissected bone marrow cells for the presence of KIT D816V. (A–D) Bone marrow sections in a patient with AML and associated systemic mastocytosis (SM) were stained with an antibody against tryptase (for mast cell detection) (A,B) and an antibody against CD34 (for detection of AML blasts) (C,D). Images were taken before (A,C) and after (B,D) microdissection by lasercapturing. Microdissected cells after successful capturing are indicated by white spots. (E–H) Melting point analysis for the presence of KIT D816V in microdissected cells in two patients with SM and associated AML (SM‐AML). In each case, HMC‐1 cells were run in parallel as an internal positive control. In one patient (E,F), CD34+ AML blast cells did not exhibit KIT D816V (E) whereas mast cells (F) clearly expressed KIT D816V. In the second patient, both the AML blasts (G) and the mast cells (H) were found to carry the KIT D816V mutant.