What are the other Names for this Condition? (Also known as/Synonyms)

• Brunnian Adenoma
• Brunnian Adenoma of the Urinary Bladder
• IUP (Inverted Urothelial Papilloma)

What is Inverted Urothelial Papilloma? (Definition/Background Information)

• Inverted Urothelial Papilloma (IUP) is a rare benign tumor of the urinary bladder that is mostly seen in elderly adults, particularly in men. The cause of formation of IUP is unknown
• However, Inverted Urothelial Papillomas may be associated with smoking, repeated bladder infections, and conditions that cause the irritation and inflammation of urinary bladder
• Most tumors are small, asymptomatic, and solitary in nature. Large-sized tumors may cause frequent urination or urinary retention, blood in urine, and abdominal discomfort. Occasionally, recurrent tumors may be associated with a higher risk for bladder cancer
• The healthcare provider may undertake a surgical removal of symptomatic Inverted Urothelial Papillomas. The prognosis is excellent on a complete removal of the tumor, since it is a benign tumor

Who gets Inverted Urothelial Papilloma? (Age and Sex Distribution)

• Inverted Urothelial Papillomas are uncommon tumors that constitute less than 1% of all urinary bladder tumors
• They may arise in individuals of any age group; an age range of 9 to 88 years is noted. However, most of the cases are reported in middle-aged and older adults in the 50 to 70 years’ age group
• Both male and females are affected, but a male predominance is observed; male-female ratio is between 6:1 to 7:1
• The condition is observed worldwide; all racial and ethnic groups are affected

What are the Risk Factors for Inverted Urothelial Papilloma? (Predisposing Factors)

The following risk factors are associated with Inverted Urothelial Papilloma:

• Chronic irritation and inflammation of the urinary bladder
• Frequent bladder infections
• Urinary bladder outlet obstructions
• Presence of bladder stones
• History of smoking

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Inverted Urothelial Papilloma? (Etiology)

The cause of formation of Inverted Urothelial Papilloma is generally unknown.

• It is thought to develop because of chronic irritation or inflammation affecting the urinary bladder from various factors
• Some researchers believe that it may be developing from hyperplasia of von Brunn nests, as a benign reactive process

What are the Signs and Symptoms of Inverted Urothelial Papilloma?

In many cases, Inverted Urothelial Papilloma does not present any significant signs and symptoms. In some cases, the following may be noted:

• The tumor size is usually less than 3 cm; although, sometimes, it can be as large as 8 cm
• Most of the tumors are single or solitary in nature; rarely, multiple tumors may be noted in the urinary bladder (in about 3% of the cases)
• Abdominal discomfort
• Painless gross hematuria (blood in urine), which is visible to the naked eye
• Microscopic hematuria, on examination of urine during a lab test
• Presence of pus in urine
• Increased frequency of urination
• Acute urinary retention; when the individual is unable to pass urine, even though the bladder is full

Inverted Urothelial Papillomas may develop in the neck region or trigone of the urinary bladder. It may also form in the prostatic urethra and lateral/posterior bladder wall.

How is Inverted Urothelial Papilloma Diagnosed?

Inverted Urothelial Papilloma is often an incidental finding, when the individual is being examined for other medical conditions. The following tests and exams may be performed:

• Complete evaluation of medical history along with thorough physical exam
• Urinalysis or urine tests
• Urine culture, to check for an infection
• Cystoscopy: Special instruments are used to visually examine and study the insides of the urinary bladder
• CT or MRI scan of the abdominal region
• Tissue biopsy: A tissue biopsy is performed and sent to a laboratory for a pathological examination, who examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

Based on pathology lab studies, Inverted Urothelial Papilloma is classified into the following two types:

• Trabecular type (also known as the classic type)
• Glandular type

The healthcare provider may undertake a differential diagnosis to eliminate other conditions or tumor types, before arriving at a definitive diagnosis. This may include the following:

• Adenocarcinoma in situ of the urinary bladder
• Cystitis glandularis
• Invasive urothelial carcinoma
• Papillary urothelial neoplasm of low malignant potential
• Tubular adenoma of the urinary bladder
• Urothelial carcinoma in situ involving von Brunn nests
• Urothelial carcinoma, nested variant
• Von Brunn nest hyperplasia

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Inverted Urothelial Papilloma?

There are usually no major complications from Inverted Urothelial Papilloma, particularly if the tumors are small-sized. In some cases, the tumors may present the following complications:

• Emotional stress due to concerns of bladder tumor
• Obstruction to the passage of urine
• Increased risk for urinary tract infections
• Damage to the muscles, vital nerves, and blood vessels, during surgery
• Post-surgical infection at the wound site
• Tumors that recur following surgery are associated with an increased risk for bladder cancer (in 2.5% to 10% of the cases)

The recurrence risk is generally less than 5%, although an incomplete resection of the tumor can result in higher recurrence rates.

How is Inverted Urothelial Papilloma Treated?

When required, and based on a qualified healthcare provider’s evaluation, a surgical excision and removal of Inverted Urothelial Papilloma can result in a cure.

How can Inverted Urothelial Papilloma be Prevented?

Presently, it is not possible to prevent the occurrence of an Inverted Urothelial Papilloma. However, the following may be noted:

• Take early appropriate treatment for conditions such as bladder infections or bladder stones
• Ensure adequate care while performing medical procedures involving the urinary bladder

What is the Prognosis of Inverted Urothelial Papilloma? (Outcomes/Resolutions)

• The prognosis of Inverted Urothelial Papilloma is typically excellent, since it is a benign tumor
• With adequate treatment i.e., surgical removal of the tumor, it can result in a cure. However, rare cases of recurrence are reported

Additional and Relevant Useful Information for Inverted Urothelial Papilloma:

Please visit our Kidney & Bladder Health Center for more physician-approved health information:

https://www.dovemed.com/healthy-living/kidney-health/