Urothelial papilloma

By Jason Wasserman MD PhD FRCPC
January 5, 2024

A urothelial papilloma is a noncancerous type of tumour. It is commonly found in the bladder although it can develop anywhere along the urinary tract. While some tumours may regrow after surgery, this type of tumour will not change into cancer over time.

This article will help you understand your diagnosis and your pathology report.

The urinary tract

The urinary tract is a system designed to help remove waste and excess water from the body through the production of urine. The urinary tract includes the kidneys, ureters, bladder, and urethra. Urine made in the kidneys flows into the bladder by way of the ureters. The bladder stores the urine until it is released from the body by way of the urethra. The inside surface of the entire urinary tract is lined by specialized urothelial cells that form a barrier called the urothelium.

What are the symptoms of a urothelial papilloma?

The most common symptom of a urothelial papilloma is bloody urine. Other symptoms include discomfort when urinating (dysuria) or the need to urinate more frequently.

What causes a urothelial papilloma?

The cause of urothelial papilloma is unknown.

Urothelial papilloma

Urothelial papilloma is made up of urothelial cells normally found on the inside surface of the urinary tract. When examined under the microscope the urothelial cells form long-finger-like projections of tissue. Pathologists describe this pattern of growth as papillary or exophytic. The tumour grows on the surface of the tissue.

What is the difference between urothelial papilloma and papillary urothelial carcinoma?

Although the names sound similar, there is a very big difference between a urothelial papilloma and papillary urothelial carcinoma. Most importantly, a papilloma is a benign (noncancerous) type of tumour that is unlikely to grow back after being removed. In contrast, papillary urothelial carcinoma is a malignant (cancerous) type of tumour that can grow back and spread to other parts of the body.

How is this diagnosis made?

Your doctor may suspect that you have this kind of tumour after examining the inside of your bladder with a camera called a cystoscope. The diagnosis, however, can only be made after the tumour is removed and sent to a pathologist for examination under the microscope.

About this article

This article was written by doctors to help you read and understand your pathology report. Contact us if you have any questions about this article or your pathology report. Read this article for a more general introduction to the parts of a typical pathology report.

Other helpful resources

Atlas of Pathology