Sample 1

Sample 2

Sample 3

Sample 4

Slide 2 contains four lesions that are typical of spontaneous tumors induced by MMTV. However, two of the lesions (Samples 1 and 2) were induced by transgenes rather than the virus. Slide Sample 2-1 has a typical solid pattern of growth that has some glandular differentiation and is refered to as a Type B tumor in the Dunn Classification. However, this tumor was induced by the wnt10b transgene (Leder and Lane). Sample 2 has the peculiar hyperplastic pattern seen in GR/A and RIII mice known as the hormone dependent tumor or "plaque". However, this particular hyperplasia is induced by the KGF transgene (Leder and Kitsberg). Sample 3 has the microacinar pattern of a MMTV-induced mammary tumor. Sample 4 has a mixture of Type B and glandular and was induced by MMTV.

October 9, 1999