So the pathologist is just judging by appearence, and not differences in the cell level? Remember he's just analyzing a part of the tumor. I assume that if your correct, he's going by the photo that accompanied the sample?
Both the papillary form and the CIS form are manifestations of transitional cell uretheral carcinoma, arising the the same cells in the bladder lining. Papillary look like little mushrooms protruding into the bladder space and can be either high grade or low grade....only the pathology can tell which. CIS (carcinoma in situ) appears as a rash or irritation on the surface of the bladder, looking very different from the papillary tumors. It is always high grade. It is quite easy for the pathologist to tell the difference between the two.
Diagnosis 2-08 Small papillary TCC; CIS
BCG; BCG maintenance
Vice-President, American Bladder Cancer Society
When a pathologist gets a sample to analyze how does he or she tell whether the tumor is a papillary tumor or a CIS tumor? I'm sure that he or she would go by something more analytical than appearence and texture.