Penis - Fibrosis. The large space (asterisk) is an artifact. The urethra is markedly dilated (arrow) in a male B6C3F1 mouse from a chronic study.
Penis - Fibrosis. Higher magnification of Figure 1 showing the dilated urethra (asterisk) lined by flattened epithelium and pieces of stratified squamous epithelium trapped in the fibrotic reaction (arrows) in a male B6C3F1 mouse from a chronic study.