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||TGF beta 1HT/activated
by crossing C57BL TGF beta 1 (+/-) with C57BL6SV129 that are heterozygous
for activated K-ras (one allele disrupted by homologous recombination)
lobes, nodules (25 total)
|Method of Fixation:
adenoma with areas borderline to carcinoma.
There are multiple variably sized densely cellular neoplastic areas most
of them expansive and well demarcated with sharp limits and few of them blending with the adjacent pulmonary parenchyma.
Growth in airways may be interpreted as an indication of
invasion. Some of the large areas replace complete lung lobules. The neoplastic
cells vary from a solid to papillary architecture supported by a delicate fine fibrovascular stroma.
The neoplastic cells are arranged in irregular undulating cords or small
nests of short cuboidal epithelial cells with a compact appearance. The
cells have moderate amounts of eosinophilic cytoplasm and oval
to round nuclei with dense chromatin. In some of the areas the neoplastic
cells have foamy cytoplasm. There are occasional large
to small areas of acidophilic macrophages, a few of them are binucleated. There are few numbers of neutrophils.