Plate 5 illustrates the typical MMTV-induced "spontaneous" mouse mammary tumors (Figures 5A and 5B) as described by Dr. Thelma Dunn with comparisons with transgene associated mammary tumors (Figures 5C to 5F).

A. Microscopic image of a Dunn Type A tumor. Note the proliferation of small acinar structures and loose connective tissue stroma (~400x).
B. Microscopic image of a Dunn Type B tumor. Note the more solid appearance of the proliferating cells with a peripheral palisade of tumor cells surrounding the cords of cells. Some glands and glandular cysts may be present(~400x).
C. Microscopic image of a tumor from a mouse with the wnt 10b transgene. This tumor is identical to Dunn Type A tumor (Figure 5A) (~400x).
D. Microscopic image of a tumor from a mouse with the myc transgene. Note that the tumor forms irregular glands lined by cells with large pleomorphic nuclei and dark (amphophilic) cytoplasm (~400x).
E. Microscopic image of a tumor from a mouse with the neu transgene. Note that this has a cell type intermediate between the myc and ras tumors and a nodular, solid pattern (~400x).
F. Microscopic image of a tumor from a mouse with the ras transgene. Note that these tumor cells are small and have a dense (red) cytoplasm. The tumor has a papillary appearance that resembles the transitional cell of the human bladder (~400x).