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

• Inflammatory Fibrosarcoma of Urinary Bladder
• Inflammatory Pseudotumor of Urinary Bladder
• Plasma Cell Granuloma of Urinary Bladder

What is Inflammatory Myofibroblastic Tumor of Urinary Bladder? (Definition/Background Information)

• Inflammatory Myofibroblastic Tumor of Urinary Bladder is a very rare, mostly benign tumor of the urinary bladder. Though IMT is an uncommon tumor, within the genitourinary system, the urinary bladder is a common site
• Inflammatory myofibroblastic tumor (IMT) is generally considered as a benign tumor with aggressive behavior (low-grade tumor), which can occur anywhere in the body
• The cause of Inflammatory Myofibroblastic Tumor of Urinary Bladder is generally unknown. There are also no well-established risk factors for this tumor type
• The signs and symptoms are generally non-specific, but may include blood in the urine, difficulties while urinating, and bladder inflammation. Complications, such as bladder dysfunction due to obstructive signs and symptoms, are known to occur
• The mainstay of treatment is a surgical excision that can be curative. Some tumors are known to shrink and disappear with time
• The prognosis of Inflammatory Myofibroblastic Tumor of Urinary Bladder is generally good on complete tumor removal, but some tumors are known to recur and even metastasize (in very rare cases)

Who gets Inflammatory Myofibroblastic Tumor of Urinary Bladder? (Age and Sex Distribution)

• Inflammatory Myofibroblastic Tumor of Urinary Bladder is typically seen in young adults and children. It can also affect elderly adults.
• Very few cases of IMT of Urinary Bladder have been recorded in the medical literature. It is a very rare tumor type
• Both males and females are affected and no gender preference is seen. A predilection for male adults is noted in some studies, while other studies indicate a slight female predilection
• All races and ethnic groups are at risk for the condition

Note: Most inflammatory myofibroblastic tumors are found in the lung, which is the most common site of the tumor. In such cases, these tumors are frequently diagnosed in middle-aged adults. However, in contrast, the average age of presentation for extrapulmonary IMT (IMT outside the lung) is around 10 years.

What are the Risk Factors for Inflammatory Myofibroblastic Tumor of Urinary Bladder? (Predisposing Factors)

Presently, the specific risk factors for Inflammatory Myofibroblastic Tumor of Urinary Bladder are unknown or unidentified. However, since the tumor occurs in the bladder (genitourinary tract), it is believed that the following factors may influence the condition:

• Smoking
• Previous history of surgery in the urinary and bladder system

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones 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 Inflammatory Myofibroblastic Tumor of Urinary Bladder? (Etiology)

The cause of development of Inflammatory Myofibroblastic Tumor of Urinary Bladder is generally unknown.

• Some research scientists believe that the cause of the condition is mostly due to genetic mutations, which results in tumor formation. In over 40% of the tumors, ALK gene mutation has been observed
• Some believe that the inflammatory myofibroblastic tumor is the result of an inflammatory reactive process and that it is not a true tumor
• It is also believed by some researchers that the tumor may arise due to viral infections caused by human herpes virus 8 (HHV8) or Epstein-Barr virus (EBV)

What are the Sign and Symptoms of Inflammatory Myofibroblastic Tumor of Urinary Bladder?

The signs and symptoms depend on the size of the tumor. The signs and symptoms of Inflammatory Myofibroblastic Tumor of Urinary Bladder can be non-specific and may include:

• Small tumors usually do not cause any symptoms. But, occasionally they may become painful, if they compress surrounding structure
• The most common symptom is blood in urine, without the presence of pain (known as painless hematuria)
• Chronic pain in the pelvis
• Difficulty in urinating; presence of burning sensation
• Feeling of obstruction while urinating
• Inflammation of the bladder (cystitis)
• Increased frequency of urination
• Abdominal pain may occur in some cases
• It is uncommon to find fever and weight loss associated with IMT of Bladder

The Inflammatory Myofibroblastic Tumor of Bladder is typically well-defined and non-homogenous in appearance. The average size of the tumor is about 4 cm.

How is Inflammatory Myofibroblastic Tumor of Urinary Bladder Diagnosed?

A diagnosis of Inflammatory Myofibroblastic Tumor of Urinary Bladder may be undertaken using the following tests and exams:

• Complete evaluation of family (medical) history, along with a thorough physical examination
• Plain X-ray of the abdomen
• Ultrasound scan of the abdomen
• CT or CAT scan with contrast of the abdomen usually shows a well-defined mass. This radiological procedure creates detailed 3-dimensional images of structures inside the body
• MRI scans of the abdomen: Magnetic resonance imaging (MRI) uses a magnetic field to create high-quality pictures of certain parts of the body, such as tissues, muscles, nerves, and bones. These high-quality pictures may reveal the presence of the tumor
• Cystoscopy: During a cystoscopy, a narrow tube called a cystoscope is inserted to look directly into the bladder. A local anesthetic is usually administered, in order to make the examination more comfortable
• Intravenous pyelogram (IVP): Intravenous pyelogram is a technique using X-rays, to examine the kidneys, bladder, and ureters (the tubes that transport urine from the kidneys to the bladder), by using a dye to highlight the duct systems. Any signs of abnormalities can be visualized using an IVP

Invasive diagnostic procedures such as:

• Laparoscopy: A special device is inserted through a small hole into the abdomen, to visually examine it. If necessary, a tissue sample is obtained for further analysis. Exploration of the abdomen using a laparoscope is called ‘exploratory laparoscopy’
• Laparotomy: The abdomen is opened through an incision for examination, and if required, a biopsy sample obtained. Exploration of the abdomen using laparotomy procedure is called ‘exploratory laparotomy’

Although the above modalities can be used to make an initial diagnosis, a tissue biopsy of the tumor is necessary to make a definitive diagnosis to begin treatment. The tissue for diagnosis can be procured in multiple different ways which include: 

• Fine needle aspiration (FNA) biopsy of the tumor: A FNA biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a FNA biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred
• Core biopsy of the tumor
• Open biopsy of the tumor

Tissue biopsy of the tumor:

• A tissue biopsy of the nodule is performed and sent to a laboratory for a pathological examination. A pathologist 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. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
• Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies to assist in the diagnosis

Note: Inflammatory Myofibroblastic Tumors are very rare. Due to this, it typically causes diagnostic challenges to the pathologist while trying to establish an accurate diagnosis.

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 Inflammatory Myofibroblastic Tumor of Urinary Bladder?

Some potential complications of Inflammatory Myofibroblastic Tumor of Urinary Bladder include:

• They can mimic bladder cancer and cause considerable emotional stress in the affected individual
• Recurrence of the tumor after treatment, especially due to partial removal of IMT (which can take place in 25-30% of the cases)
• Urinary bladder dysfunction due to large tumors

IMTs are considered to be low-grade tumors and in a majority of individuals, they do not show any malignancy (95% or more cases). However, in about 5% of the individuals, the tumor can undergo a malignant transformation (called Malignant Inflammatory Myofibroblastic Tumor). In such cases, metastasis has been observed that may even result in fatal outcomes.

How is Inflammatory Myofibroblastic Tumor of Urinary Bladder Treated?

Inflammatory Myofibroblastic Tumor of Urinary Bladder may be treated through the following measures:

• Surgery for early-stage IMT of Urinary Bladder: If the tumor is small and has not spread to the urinary bladder wall, the surgical treatments a physician may recommend include:
  • Transurethral resection of bladder tumor (TURBT): During this procedure, a small wire loop is used to pass through the urethra and into the bladder. This loop uses an electric current (fulguration) to burn away the cancer cells. However, following this procedure, there may be painful or bloody urination
  • Segmental cystectomy: During a segmental cystectomy (also known as partial cystectomy), the part of the bladder that contains the cancer cells is removed by a surgeon. If the cancer is confined to a certain area of the bladder, segmental cystectomy may be an option and a part of the bladder can be removed without damaging bladder function
• Surgery for advanced IMT of Urinary Bladder: In extreme case, the healthcare provider may recommend a radical cystectomy (removal of the entire bladder)
• In young children, if the tumors cannot be surgically removed, then corticosteroid administration is found to be beneficial
• Occasionally, some tumors are known to disappear over time, without any treatment
• Chemotherapy may help, if the condition recurs , if there is a local invasion, or a distant metastasis is noted (in very rare cases)

Observation and periodic checkups to monitor the condition is recommended following treatment.

How can Inflammatory Myofibroblastic Tumor of Urinary Bladder be Prevented?

Presently, there are no specific methods or guidelines to prevent Inflammatory Myofibroblastic Tumor of Urinary Bladder.

What is the Prognosis of Inflammatory Myofibroblastic Tumor of Urinary Bladder? (Outcomes/Resolutions)

• An early diagnosis and prompt treatment of Inflammatory Myofibroblastic Tumor of Urinary Bladder generally yields better outcomes than a late diagnosis and delayed treatment
• The prognosis on timely surgical removal of the entire tumor is generally good. Some tumors are known to spontaneously regress and disappear
• Some tumors are known to recur following treatment. In rare cases, metastatic tumors are also observed; in which case, the prognosis may be unpredictable

Additional and Relevant Useful Information for Inflammatory Myofibroblastic Tumor of Urinary Bladder:

The following article link will help you understand other cancers and benign tumors:

http://www.dovemed.com/diseases-conditions/cancer/

The following article link will help you understand other urinary bladder conditions:

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