Figure 3.

Tp53^C273X predominantly develop sarcomas. A: Representative image of clusters of plump, pleomorphic tumor cells separated by blood-filled spaces, morphologically consistent with hemangiosarcoma. B: Marked Factor VIIIra immunoreactivity in intravascular pulmonary metastasis of hemangiosarcoma. Note positivity in pre-existing, non-neoplastic endothelium (internal positive control). C: Tumor emboli in pulmonary blood vessels consist of cells highly pleomorphic cells with indistinct cell borders and variably sized nuclei. D: Monotonous population of neoplastic lymphocytes obscuring the normal architecture of the spleen. E: Infiltration of neoplastic lymphocytes into a hemangiosarcoma from the same animal. CD79a immunoreactivity indicates B-cell origin. F: Abdominal mass from the region of the left adrenal. Small polygonal, relatively uniform cells aligned along fine fibrovascular stroma as is typical for endocrine tissue. G: Only rare activity for neuron-specific enolase was observed in the neoplasm shown in F, consistent with adrenocortical origin. H: Hind limb neoplasm in heterozygous p53 mutant rat. Neoplastic spindle cell concentrically arranged around islands of partly mineralized bone, consistent with osteosarcoma. I: Rhabdomyosarcoma showing multinucleate cells with rows of nuclei and cytoplasmic and nuclear MyoD1 immunoreactivity.