Histology and ultrastructure of the R-3327 C-F transplantable prostate tumor of Cophenhagen-Fisher rats

The R-3327 C-F tumor is an adenocarcinoma of the prostate maintained by serial transplantation in male Copenhagen-Fisher hybrid rats. The tumor is histologically different from other tumor sublines derived from the original R-3327 tumor discovered in 1961 in an aged Copenhagen rat. Light and electron microscopy have shown that the R-3327 C-F tumor contains a well organized glandular epithelium with myoepithelial cells and a continuous basement membrane, although epithelial cells were much less differentiated than epithelial cells of either dorsal or lateral normal prostate of the rat. Two features of interest were the presence of large, abnormal fibroblasts in stroma, and of lymphocytes embedded in the epithelium. Virus particles have not been observed in the specimens examined by electron microscopy.