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

• IMT of Jaw
• Mandibular Inflammatory Myofibroblastic Tumor
• Maxillary Inflammatory Myofibroblastic Tumor

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

• Inflammatory Myofibroblastic Tumor of Jaw is a very rare, mostly benign tumor affecting the upper or lower jaw. Even though rare, this tumor type is generally observed in middle-aged individuals
• If the tumor affects the lower jaw, it is called Mandibular Inflammatory Myofibroblastic Tumor; if the tumor affects the upper jaw, it is called Maxillary Inflammatory Myofibroblastic Tumor
• Inflammatory myofibroblastic tumor (IMT) is typically considered as a benign tumor with aggressive behavior (low-grade tumor), which can occur anywhere in the body
• The cause of Mandibular or Maxillary Inflammatory Myofibroblastic Tumor is generally unknown. There are also no well-established risk factors for this tumor type
• From the available number of cases, this tumor seems to prefer the upper jaw (maxilla). The signs and symptoms may include jaw pain, tenderness, numbness in the region of the tumor, and eating and chewing difficulties. Complications, such as tumor recurrence on surgical removal of the tumor, is not usually known to occur
• The mainstay of treatment is a surgical excision that can be curative. The prognosis of Inflammatory Myofibroblastic Tumor of Jaw is generally good on tumor removal, but rarely some tumors are known to metastasize

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

• Inflammatory Myofibroblastic Tumor of Jaw is typically seen in middle-aged adults (average age 35 years). Very young children to older adults (over 80 years old) are known to be affected
• Very few cases of IMTs of the oral cavity have been recorded in the medical literature (less than 20 cases reported worldwide). About 1 in 5 oral cavity IMTs are Inflammatory Myofibroblastic Tumors affecting the jaw
• Both males and females are affected, but there is a slight preference for males; some studies indicate a ratio of 1.5:1 (male-female)
• 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 Jaw? (Predisposing Factors)

• Presently, the specific risk factors for Inflammatory Myofibroblastic Tumor of Jaw 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 Jaw? (Etiology)

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

The signs and symptoms depend on the size of the tumor. The signs and symptoms of Inflammatory Myofibroblastic Tumor of Jaw may include the following:

• Small tumors usually do not cause any symptoms. But, occasionally they may become painful, if they compress surrounding structure
• Depending on the jaw and jaw bone that is affected, there may be pain, swelling, tenderness, displacement or bulging of teeth, tingling sensation, numbness
• If the tumor size is large, the adjoining organs, nerves, and muscles may be compressed or restricted
• The individual may have difficulty eating, swallowing, or even breathing

The tumor is generally solid and it may grow up to 5-7 cm or more in size. It can be seen in the upper or lower jaw; mostly in the upper jaw though.

How is Inflammatory Myofibroblastic Tumor of Jaw Diagnosed?

A diagnosis of Inflammatory Myofibroblastic Tumor of Jaw 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 head and neck
• Ultrasound scan of the affected region
• CT or CAT scan with contrast of the head and neck usually shows a well-defined mass. This radiological procedure creates detailed 3-dimensional images of structures inside the body
• MRI scans of head and neck: 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
• Core biopsy of the tumor
• Open biopsy of the tumor

Tissue biopsy of the tumor:

• A tissue biopsy of the tumor 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 Jaw?

Some potential complications of Inflammatory Myofibroblastic Tumor of Jaw include:

• They can mimic oral cancer and cause considerable emotional stress in the affected individual
• Due to obstruction of the mouth, the individual may experience prolonged feeding and breathing difficulties
• The tumor mass may affect an individual’s appearance, their self-confidence, and self-esteem
• Reconstructive surgical procedures may be required to restore profile of the face
• Recurrence of the tumor after treatment, especially due to partial removal of IMT. However, no cases have been reported of IMT of Jaw recurrence

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 Jaw Treated?

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

• Surgical excision of and removal of the entire lesion is the standard treatment mode
• After surgical removal of the tumor, reconstructive surgical procedures may be planned to correct facial defects and restore the facial profile (if necessary)
• In young children, if the tumors cannot be surgically removed, then corticosteroid administration is generally found to be beneficial. However, in case of oral IMTs, studies indicate that corticosteroid therapy is not very effective
• Chemotherapy may help, if the condition recurs , if there is a local invasion, or a distant metastasis is noted (in very rare cases)
• Occasionally, some tumors are known to disappear over time, without any treatment

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

How can Inflammatory Myofibroblastic Tumor of Jaw be Prevented?

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

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

• An early diagnosis and prompt treatment of Inflammatory Myofibroblastic Tumor of Jaw generally yields better outcomes than a late diagnosis and delayed treatment
• The prognosis on timely surgical removal of the tumor is generally good. On a complete excision and removal, the available cases indicate that IMT of Jaw is not likely to recur
• Some tumors are known to spontaneously regress and disappear. But, some tumors are known to recur or even metastasize (very occasionally)

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

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

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