There are several different types of bladder cancer.
Urothelial carcinoma, also known as transitional cell carcinoma (TCC), is by far the most common type of bladder cancer.
Transitional cell urothelial carcinoma or carcinoma
Transitional cell carcinoma (TCC) is by far the most common type of bladder cancer.
This type of cancer is born at the level of the most inner layer of the bladder wall, the urothelium, the bladder mucosa. Urothelium is the coating of all canals and structures of the urinary tract. It is directly in contact with the urine.
This is how urothelium coats the walls of the kidneys, ureters and urethra.
It may remain superficial non-invasive, limited to urothelium, or pass through the basal membrane and become superficial-invasive, then invade the bladder muscle, detrusor, and become infiltrating.
Patients with bladder cancer may also have other tumours in these other canals and structures covered by urothelium. This is why the entire urinary tract must be investigated as part of the tumour extension assessment when diagnosed.
Other bladder cancers
There are several other types of bladder cancer that are much rarer than the classic transitional cell urothelial carcinoma.
- Squiggle cell carcinoma:
In the United States, it accounts for 1-2% of bladder cancers.
Under a microscope, the cells are very similar to the epithelial cells of human skin.
Virtually all squamous cell tumours are invasive.
It accounts for about 1% of bladder tumours.
Cancer cells are very similar to gland cells found in colon cancer.
Virtually all bladder adenocarcinomas are invasive tumours.
- Small cell bladder carcinoma:
Less than 1% of bladder tumours are small cell cancers.
The cells that make them up look a lot like neurons, the cells of the nervous system.
They’re called neuroendocrine cells.
These cancers are often of rapid development and traditionally it is necessary to treat them with chemotherapy, which is identical to that used for the treatment of small cell lung cancer.
- The sarcoma:
Sarcomas develop from the muscle cells of the bladder wall. These are rare tumours.
With the exception of sarcoma, these rare bladder cancers are treated in the same way as transitional cell carcinoma, especially in the early stages of disease. However, if chemotherapy is necessary, the drugs used are different.
- National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Bladder Cancer. V. 2.2015. Accessed at www.nccn.org/professionals/physician_gls/pdf/bladder. pdf on January 14,2016.
- Smith A, Balar AV, Milowsky MI, Chen RC. Chapter 83: Bladder Cancer. In: Niederhuber JE, Armitage JO, Dorshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 5th ed. Philadelphia, Pa. Elsevier: 2014.