Figures 10–12.

Figures 10 and 11. Histiocytosis, spleen (Figure 10) and bone marrow (Figure 11), NSG mouse implanted with transduced hCD34+ cells (mouse no. 25). HE. Figure 12. Histiocytosis, liver, NSG mouse implanted with a B-ALL patient-derived xenograft (mouse no 27). (a) Multifocal aggregates of macrophages are randomly scattered throughout the liver. HE. (b) The large cells have abundant cytoplasm. HE. Inset: positive immunolabeling for hNuMA1, confirming the human origin of the cells. (c–e) Macrophages are positive for hCD68 (c) and hCD163 (d), and the aggregates are surrounded by hyperplastic F4/80-positive mouse cells (e). (f) Iron is not detected in the macrophage cytoplasm. Prussian blue. (g, h) Scattered among the macrophages are small numbers of small cells immunolabeled for hCD45 (g) and CD3 (h).