What is bladder cancer?

What is bladder cancer?

The bladder, a hollow organ in the lower part of the abdomen, serves as a reservoir for urine until it is discharged out of the body through the urethra.

There are different types of bladder cancer. The cancer cell type can be transitional cell carcinoma, squamous cell carcinoma or adenocarcinoma—each named for the types of cells that line the wall of the bladder where the cancer originates.

• Most bladder cancers (more than 90 percent) start from the transitional cells, which occupy the innermost lining of the bladder wall. The cancers, which originate in these cells lining the bladder can, in some instances, invade into the deeper layers of the bladder (called the lamina propria), the thick muscle layer of the bladder, or through the bladder wall into the fatty tissues that surround the bladder.
• Squamous cells are thin flat cells that line the urethra and can form in the bladder after long bouts of bladder inflammation or irritation. Squamous cell carcinoma makes up about 5 percent of bladder cancers.
• Adenocarcinoma is a very rare type of bladder cancer that begins in glandular (secretory) cells in the lining of the bladder. Only 1 percent to 2 percent of bladder cancers are adenocarcinoma.