Types

Histological types

Urothelial carcinoma (transitional cell carcinoma), originating from the urothelial cells it is the most common type. Urothelial cells line the urinary tract, including the renal pelvis, ureters, bladder, superior urethra, and the central ducts of the prostate. They act as a permeability barrier and protect underlying muscle tissues from the caustic effects of urine. They are highly elastic and alter their shape (hence the name transitional cells) depending of the volume of the urinary bladder.

Squamous cell carcinoma, occurring when transitional bladder cells transform to squamous cells (thin, flat cells lining the inside of the bladder) due to chronic irritation. It is commonly caused by schistosomiasis in Africa and the Middle East.

Adenocarcinoma, originating from mucus producing glandular cells that are found in the lining of the bladder.

Small cell carcinoma, originating from neuroendocrine cells (nerve-like cells that release hormones into the blood in response to a signal from the nervous system).

Types based on bladder muscular invasion

Non-muscle-invasive bladder cancer in which malignant cells do not attack bladder muscular wall.

Muscle-invasive bladder cancer in which malignant cells spread through the lining of the bladder and into the muscle wall of the bladder or beyond it.