<s>[INST] how serious is a mass in the bladder - my husband having a procedure on Friday to remove the mass and said it looks like it is cancer - they are going to scrape it all off and send it to pathology...why would he say it is cancer when it isnt out yet [/INST] Hi and welcome to Chat Doctor. Thanks for the query. There are some morphological features which indicate malignancy and doctor can guess that it is cancer. Of course to be 100% biopsy must be done. But doctor have experience and in many cases then can determine what kind of tumor it really is even without further tests. But whatever it is, biopsy must be done, and further treatment depends on it. Wish you good health. Regards </s>