Morphology of tumors detected in ENU-treated PR+ F2 mice. (A-C) Myeloproliferative disease, (D-F) myeloid leukemia, (G-I) lymphoma, (A,D,G) peripheral blood, (B,E,H) bone marrow, and (C,F,I) spleen. (A) Normal lymphocyte and neutrophil. (B) Mild myeloid hyperplasia (secondary to the PR transgene) and normal maturation of all lineages. (C) Normal splenic architecture. (D) Clusters of immature myeloid cells in the peripheral blood. (E) Left shift and expansion of the myeloid lineage in the bone marrow. (Inset) Myeloperoxidase positive blasts. (F) Effacement of splenic architecture by leukemic blasts. (G) Immature lymphoid cells in peripheral blood. (H) Infiltration of bone marrow by malignant lymphocytes. (I) Effacement of splenic architecture by lymphoma cells. Original magnification: ×50 (A), ×40 (C,F,I); ×100 (all others). Images were obtained using a BX40 microscope (Olympus, Center Valley, PA) with UPlanFl 40×/0.75, Plan 50×/0.90 oil iris, and UplsnFl 100×/1.30 oil ∞/0.17 objective lenses. DP70 camera and DP controller software version 2.2.1.227 (Olympus) were used for image acquisition. Photoshop 7.0 (Adobe Systems, San Jose, CA) was used for image preparation.
