(a) Hematoxylin and eosin stain, showing the gastric biopsy with leukemic infiltrate in the stroma consisting of monomorphous medium sized cells with dispersed but clumped chromatin insinuating in between the normal gastric glands without destruction. Inset shows the high power view (40x magnification) of these leukemic cells. These neoplastic cells express CD34 (b) and CD117 (c). FISH evaluation (d) was performed on this gastric biopsy using X and Y DNA probe set and revealed an XX signal configuration (arrow) in the cells of the leukemic infiltrate which is consistent with female donor chromosome complement and the expected XY configuration (arrowhead) in the gastric tissue consistent with male chromosome complement of this patient.
