Ultrasound Result, Cancer Risk, Removal

A polyp is an abnormal mass of tissues arising from the mucous membrane of organs, including the bladder. Some bladder tumors are benign (noncancerous), while others can gradually change and become malignant (cancerous).

If your healthcare provider finds a bladder polyp, they may recommend that you have it removed based on its size and appearance. Certain features may suggest that a polyp is more likely to turn cancerous or already have cancer cells in them.

By having a suspicious polyp removed, you can prevent it from becoming malignant or prevent the spread of cancer if the mass is already malignant.

Bladder Polyps on Ultrasound: How Symptoms Get Diagnosed 

Many people with bladder polyps are asymptomatic, meaning that they have no symptoms. If symptoms develop, you may experience:

• The need to pee frequently (urinary frequency)
• The need to pee urgently (urinary urgency)
• Difficulty starting or maintaining a urine stream (urinary hesitancy)
• Pain or burning with urination (dysuria)
• Pink- or orange-hued blood in your urine (hematuria)

If symptoms like these develop, you may be referred to a urologist or urogynecologist (specialists in urinary tract conditions).

The specialist will review your medical history and perform a physical exam as part of the evaluation. The physical exam would involve palpation (examining by light touch) of the abdomen and pelvis to check for signs of swelling or pain. A pelvic exam or a digital rectal exam might also be performed.

Other tests and procedures can help diagnose bladder polyps:

• Bladder ultrasound: This noninvasive imaging tool uses high-frequency sound waves to generate and capture live images of the bladder.
• Cystoscopy: This direct method of detection involves inserting a narrow scope—called a cystoscope—into your urethra (the tube through which urine exits the body) to examine the inside of your bladder.
• Imaging studies other than ultrasound: Computed tomography (CT) or magnetic resonance imaging (MRI) can provide more detailed images of the growth before invasive procedures are performed.
• Urinalysis: This test can detect abnormalities in a urine sample, including signs of unseen bleeding (microscopic hematuria).
• Urine cytology: This microscopic examination of a urine sample checks for precancerous or cancerous cells.

Cystoscopy can also be used to remove polyps or any other abnormal growth.

Causes and Risk Factors

The exact cause of polyps—why they occur and why some become cancer—is unknown. In most cases, polyps have no known cause.

With that said, certain factors can increase the risk of polyps. These include being male (which increases the risk by up to fourfold compared to females) and being over the age of 55.

Other risk factors include:

• Bladder irritation caused by recurrent urinary tract infections (UTIs), kidney or bladder stones, medical procedures (like cystoscopy), or the prolonged use of urinary catheters
• Certain noninheritable genetic mutations, like the FGFR3, PIK3CA, KDM6A, and TP53 mutations commonly associated with bladder cancer
• Family history of bladder polyps or cancer
• Heavy cigarette smoking (more than three times daily)
• Prolonged industrial exposure to toxins like benzene, xylene, and polyaromatic hydrocarbons used in the manufacture of plastic, rubber, leather, textiles, paint, and dyes

Risk of Cancer With Bladder Polyps

Bladder cancer is a relatively rare form of cancer. It affects just 18 out of every 100,000 people of any sex in the United States each year. It accounts for 4% of all cancers in the United States.

As an entity, bladder polyps are also uncommon and fall into two broad categories. each with a different risk of malignancy:

• Neoplastic polyps are precancerous and, if given time, can turn cancerous. Neoplasm refers to the excessive, abnormal growth of cells that form tumors.
• Nonneoplastic (or hyperplastic) polyps are small polyps that are almost invariably benign. Hyperplasia refers to the increased production of normal cells.

There are three factors that can predict the risk of malignancy: the type of bladder polyp you have, the size of the polyp, and the physical characteristics of the polyp.

Bladder Polyp Types

There are different neoplastic and nonneoplastic polyps, which vary by their appearance. In some cases, the appearance of a polyp can provide a high certainty as to whether it is benign or malignant.

The appearance of a polyp may be described as sessile (flat or slightly elevated), pedunculated (having a mushroom shape with a stalk), or serrated (having a sawtooth appearance). These variations can also make certain polyps easier or harder to find and remove.

Nonneoplastic

Nonneoplastic bladder polyps are less common than neoplastic ones, accounting for only around 5% of bladder masses. Some share characteristics of neoplastic polyps and require a pathologist to make the distinction.

The two main types of benign bladder polyps are:

• Inverted urothelial papillomas: These growths are benign but aggressive, starting on the epithelium but growing into underlying tissues. They are exceptionally rare, with only 1,000 cases reported in the medical literature. Inverted papillomas look similar to FEPs but tend to be small, solitary, and situated on the bladder wall.
• Urothelial polyps: Also known as fibroepithelial polyps (FEPs), these arise from the lining of the bladder, known as the epithelium. They tend to be small, solitary, pinkish or white, and either sessile or pedunculated. Most are located near the bladder neck and are generally slow-growing. On the skin, FEPs are known as skin tags.

Other rare benign bladder growths include:

• Hemangioma: This is an abnormal cluster of blood vessels that are sessile and look like a rubbery bump or flat red patch. On the skin, they are known as birthmarks.
• Leiomyoma: This is a smooth, self-contained lump that starts in the smooth (involuntary) muscle of the bladder. In the uterus, it is called a uterine fibroid.
• Lipoma: These are solitary, rubbery masses that start in the fat layer of the bladder. Lipomas can grow to a significant size and can cause blockages if they get large.
• Neurofibroma: This is an abnormal clump of nerves in the bladder. Neurofibromas are usually solitary, appearing as smaller bumps (papules) or larger nodules.

Neoplastic

Adenomas are the main type of neoplasm in the bladder. They originate in mucus-producing cells of the epithelium and, while generally benign, can sometimes undergo abnormal and erratic changes to the structure and organization of cells, known as dysplasia.

Dysplasia can be low, moderate, or high grade. The more dysplastic an adenomatous polyp is, the more likely it will become cancerous.

There are three types of adenomatous polyps:

• Tubular adenomas: This rare type of adenoma is so named because it looks like an orderly row of test tubes. Tubular adenomas exhibit moderate-grade dysplasia and are least likely to become malignant.
• Tubulovillous adenomas: These share features of tubular and villous adenomas. While rare, they exhibit high-grade dysplasia, with 10% eventually becoming cancerous. These adenomas are often found on the front, top, or base of the inner bladder.
• Villous adenomas: This is the most common type that tends to be larger and have severe degrees of dysplasia. Between 15% and 25% will become cancerous. The sessile polyps are usually found on the forward-facing side of the bladder and have a cauliflower-like appearance.

In addition to adenomas, other bladder polyps are also at risk of becoming malignant:

• Hamartomatous polyps: These rare polyps occur in people with genetic conditions like Peutz-Jeghers syndrome, Cowden syndrome, or juvenile polyposis. These exhibit low-grade dysplasia and have a low likelihood of becoming cancer.
• Sessile-serrated polyps: This type is so named because they are flat and broad with a jagged border. The polyps tend to exhibit high-grade dysplasia and, because of their low profile, are harder to identify and remove and most likely to develop into cancer.

Treatment and Removal 

Not every bladder polyp needs to be removed, and benign ones may only need treatment if they are causing symptoms. This is especially true if the polyp is small and not positioned in or near a major outlet, where it may later cause obstruction.

Polyps that are large, suspicious, and causing symptoms are invariably removed. This is typically done with a procedure known as transurethral resection of bladder tumor (TURBT).

How TURBT Is Performed

TURBT is performed under general or regional anesthesia using a special type of cystoscope—called a resectoscope—that is fed through the urethra and into the bladder to remove polyps and other suspicious growths.

This resectoscope has a small electrified wire loop at the end that can simultaneously resect (remove) a polyp and cauterize (burn) underlying blood vessels to stop any bleeding. This is sometimes called fulguration.

Light-sensitive dyes may be fed into the bladder beforehand in a process as known as photodynamic diagnosis (PDD). A special blue light on the resectoscope can then highlight hot spots where cancer cells are, making it easier to find and remove less obvious polyps.

The resected polyps are then sent to a pathologist to check for signs of cancer under a microscope, special stains, and other tests.

Recovery

The TURBT procedure usually takes no longer than one hour. Once you have recovered from the anesthesia, you can return home. You may have bloody urine for up to three days and traces of blood for up to 14 days. Bleeding and bruising are common, but infection is rare.

Complications and Future Risks

The main complication of a bladder polyp is bladder cancer. The most common is urothelial carcinoma, also known as transitional cell carcinoma (TCC), but there are other rarer types known as squamous cell carcinoma, adenocarcinoma, and sarcoma.

If the pathologist finds cancer, the next step is to stage and grade the malignancy. Staging describes the size of the tumor and how far it has spread, while grading describes how aggressive (fast-growing) or indolent (slow-growing) it is.

Additional tests, such as a CT scan, may be performed to determine whether the tumor has invaded underlying bladder muscles. These findings will direct the appropriate course of treatment.

Treatment Recommendations

Even after the removal of the tumor with TURBT, up to 50% of people will experience a recurrence of cancer within 12 months.

Because of this, the American Urological Association (AUA) recommends a procedure called a radical cystectomy in cases of muscle-invasive bladder cancer (MIBC) and some cases of non-muscle-invasive bladder cancer (NMIBC). This involves the removal of the bladder, nearby lymph nodes, and some or all of the urethra.

In cases where the bladder can be spared, the AUA recommends performing a repeat TURBT in four to six weeks to see if there are any residual signs of cancer.

Prevention and How to Support Bladder Health

You can’t always prevent bladder polyps or cancer, but there are things you can do to improve your bladder health and possibly reduce your risk:

• Drink plenty of liquids each day, especially water. People who drink a lot of fluids tend to have lower rates of bladder cancer. 
• Eat a diet rich in fruits, vegetables, whole grains, and legumes (lentils, peas, and beans). There is also evidence that drinking tea may help reduce bladder cancer risk.
• Limit workplace exposure to chemicals like benzene and polyaromatic hydrocarbons, following occupational safety protocols.
• Quit all forms of smoking, including cigarettes, electronic cigarettes (e-cigarettes), cigars, and pipes. Smoking increases the risk of bladder cancer by up to sixfold.

Summary 

Bladder polyps are abnormal growths in the bladder, some of which may be benign (noncancerous) and others that may turn malignant (cancerous). Urothelial polyps and inverted urothelial papilloma are two benign polyps that can commonly affect the bladder, while adenomas and serrated-sessile polyps are two types that have a greater chance for malignancy.

Polyps can be identified with a procedure called cystoscopy. If a polyp is large, suspicious, or causing symptoms, it can be removed with transurethral resection of bladder tumors (TURBT) and minimal invasive performed under anesthesia.

In cases where bladder cancer is found, a procedure called a radical cystectomy may be needed to remove the bladder. They reduce the risk of recurrence common with bladder cancer.