urothelium

noun

uro·​the·​li·​um ˌyu̇r-ə-ˈthē-lē-əm 

plural urothelia -lē-ə 

: the transitional epithelium that lines most structures of the urinary tract

The integrity of the urothelium is preserved even when it is fully stretched to accommodate a full bladder.

—Gillian Pocock et al., Human Physiology, 4th edition

called also uroepithelium

urothelial

ˌyu̇r-ə-ˈthē-lē-əl 

adjective

urothelial cells

In view of the patient's presentation, our clinical diagnosis was urothelial carcinoma of the bladder neck, the prostatic urethra, or both.

—Aria F. Olumi et al., The New England Journal of Medicine