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

• Inflammatory Fibrosarcoma of Lung
• Pulmonary Inflammatory Pseudotumor
• Pulmonary Plasma Cell Granuloma

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

• Inflammatory Myofibroblastic Tumor of Lung is a rare, mostly benign tumor of the lung. They can grow to large sizes and are known to occur in middle-aged adults
• Inflammatory myofibroblastic tumor (IMT) is generally considered as a benign tumor with aggressive behavior (low-grade tumor), which can occur anywhere in the body
• Only around 1% of the lung tumors are inflammatory myofibroblastic tumors. Despite being very rare, the lung is the most common site of IMT involvement
• The cause of Pulmonary Inflammatory Myofibroblastic Tumor is generally unknown. There are also no well-established risk factors for this tumor type
• The tumor may be located at any location in the lung, but is mostly found in the bronchus (airways). The signs and symptoms are generally non-specific, but may include breathing difficulties, chest pain, and coughing with blood. Complications, such as fluid in the lungs or a partial lung collapse, are known to occur occasionally
• The mainstay of treatment is a surgical excision that can be curative. The prognosis is generally good on complete removal of the tumor, but some tumors are known to recur and rarely they can even metastasize

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

• Inflammatory Myofibroblastic Tumors are typically seen in young adults and children, including in newborns and infants. However, IMT of Lung is more commonly observed in middle-aged individuals
• Both males and females are affected and no gender preference is seen
• All races and ethnic groups are at risk for the condition
• Pulmonary IMT is rare, even though lung is the most common location for this tumor type. Inflammatory myofibroblastic tumors of the lung represent only 0.7-1.0% of all pulmonary or lung tumors

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

• Presently, the specific risk factors for Pulmonary Inflammatory Myofibroblastic Tumor are unknown or unidentified

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 Lung? (Etiology)

The cause of development of Inflammatory Myofibroblastic Tumor of Lung 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 Lung?

The signs and symptoms depend on the size of the tumor. In most cases, the individual may be asymptomatic. The signs and symptoms of Inflammatory Myofibroblastic Tumor of Lung may include:

• Chest pain
• Difficulty breathing
• Cough; coughing up blood that may be recurrent
• Fever and fatigue
• Rarely, there can be weight loss and loss of appetite
• Large tumors can cause other obstructive signs and symptoms
• In some cases, there may be prolonged or chronic lung infections

The lung tumor may range in size from 1-6 cm, but may reach up to 9 cm too. It is commonly seen in the bronchus (airways). The Inflammatory Myofibroblastic Tumor of Lung is typically well-defined, but not firm or uniform in appearance.

How is Inflammatory Myofibroblastic Tumor of Lung Diagnosed?

A diagnosis of Inflammatory Myofibroblastic Tumor of Lung 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 chest
• CT or CAT scan with contrast of the chest usually shows a well-defined mass. This radiological procedure creates detailed 3-dimensional images of structures inside the body
• MRI scans of the lungs: 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

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
• Open lung biopsy
• Thoracentesis: During thoracentesis, physicians use a special medical device called a cannula, to remove fluid between the lungs and the chest wall for examination
• Thoracoscopy: A medical instrument called a thoracoscope is inserted into the chest through tiny incisions, in order to examine and remove tissue from the chest wall, which is then analyzed further
• Thoracotomy: Thoracotomy is a surgical invasive procedure with special medical instruments to open-up the chest and remove tissue from the chest wall or the surrounding lymph nodes of the lungs
• Mediastinoscopy: A medical instrument called a mediastinoscope is inserted into the chest wall to examine and remove samples

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 Lung?

Some potential complications of Inflammatory Myofibroblastic Tumor of Lung include:

• They can mimic lung cancer and cause considerable emotional stress in the affected individual
• Recurrence of the tumor after treatment, which is seen in about 25-30% of the cases
• Large tumors can obstruct the bronchus (airways) and other adjoining organs/structures
• In rare cases, partial collapse of the lung
• Pleural effusion (fluid in the lungs) is seen occasionally

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 Lung Treated?

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

• Surgical removal of the entire tumor is the preferred treatment method, since Pulmonary IMT is thought to be a low-grade tumors
• The types of surgery may include:
  • Lobectomy and chest wall resection
  • Segmentectomy
  • Wedge resection
• 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 Lung be Prevented?

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

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

• An early diagnosis and prompt treatment of Inflammatory Myofibroblastic Tumor of Lung generally yields better outcomes than a late diagnosis and delayed treatment
• The prognosis on timely surgical removal of the entire tumor is generally excellent
• Some tumors are known to be locally aggressive and some can recur following treatment
• In rare cases, where there is metastasis, the prognosis is poor. Fatalities have been reported due to Pulmonary Inflammatory Myofibroblastic Tumor

Additional and Relevant Useful Information for Inflammatory Myofibroblastic Tumor of Lung:

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 lung conditions:

http://www.dovemed.com/healthy-living/healthy-lungs/