more abnormal layers when they are irritated. Chemical carcinogens, chronic bladder infections, conditions called cystitis cysticia and cystitis glandularis, and chronic and repeated bladder trauma—repeated bladder catheterizations in paraplegics, for example—can cause cell changes that may turn into cancer.
This superficial layer of transitional cells is separated from the bladder muscle (which contracts to expel urine) by a thin, fibrous band called the lamina propria. The lamina propria separates tumors that are invasive (spreading into muscle) from those that are superficial (non-invasive). Treatment options depend on this distinction. Most bladder tumors are superficial and can be treated successfully.
Most of the remaining tumors—either alone or combined with transitional cell carcinoma—develop
