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

• Inflammatory Fibrosarcoma of Bone
• Inflammatory Pseudotumor of Bone
• Plasma Cell Granuloma of Bone

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

• Inflammatory Myofibroblastic Tumor of Bone is a very rare, mostly benign tumor affecting the bone. They generally occur in younger populations
• 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 Bone is generally unknown. There are also no well-established risk factors for this tumor type
• The tumor may be located in any bone of the body such as the thighbone or the temporal bone. The signs and symptoms of Inflammatory Myofibroblastic Tumor of Bone may include bone pain and increased fracture risks. Complications, such as tumor recurrence on incomplete removal and involvement of bone marrow, is known to occur
• The mainstay of treatment is a surgical excision that can be curative. The prognosis of Inflammatory Myofibroblastic Tumor of Bone is generally good on tumor removal, but some tumors are known to recur and occasionally, even metastasize

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

• Inflammatory Myofibroblastic Tumor of Bone is typically seen in young adults and children
• Very few cases of IMT of Bone have been recorded in the medical literature
• Both males and females are affected and no gender preference is seen
• 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 Bone? (Predisposing Factors)

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

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

The signs and symptoms depend on the size and location of the tumor. The presentations of Inflammatory Myofibroblastic Tumor of Bone may include:

• Small tumors usually do not cause any symptoms
• Bone pain that may be mild
• Easy fractures
• Headache, dizziness
• Numbness in the region of the tumor
• In some cases, the bone marrow may be involved

The tumor is well-defined. It may be observed in the femur (thighbone), the temporal bone (by the side of the skull), jaw bone, among other bones.

How is Inflammatory Myofibroblastic Tumor of Bone Diagnosed?

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

• Complete evaluation of family (medical) history, along with a thorough physical examination
• Blood tests
• Imaging tests:
  • X-rays:  X-ray images of the bone reveal areas of bone reabsorption, enlargement of the bone, and other deformities
  • Bone scan: Radioactive material inserted into the body to light up the scan images
• 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 Bone?

Some potential complications of Inflammatory Myofibroblastic Tumor of Bone include:

• They can mimic cancer and cause considerable emotional stress in the affected individual
• Recurrence of the tumor after treatment, especially due to partial removal of IMT; seen only in rare cases
• Increased susceptibility to fractures due to fragility of bones
• Osteoarthritis: Deformation of the bone causes additional stress on the neighboring joints, leading to osteoarthritis
• Severe complications due to involvement of the bone marrow
• In rare cases, these tumors can be locally aggressive
• Also, very rarely, these tumors are known to metastasize; in which case the tumor is known as Malignant Inflammatory Myofibroblastic Tumor

How is Inflammatory Myofibroblastic Tumor of Bone Treated?

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

• Surgical removal of the entire tumor is the preferred method of treatment
• In young children, if the tumors cannot be surgically removed, then corticosteroid administration is found to be beneficial
• Chemotherapy may help, if the condition recurs , if there is a local invasion, or a distant metastasis is noted (in very rare cases)
• The involvement of bone marrow would necessitate additional treatment procedures such as high-dose steroids and blood transfusions
• 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 Bone be Prevented?

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

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

• An early diagnosis and prompt treatment of Inflammatory Myofibroblastic Tumor of Bone 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, IMT of Bone is generally not known to recur
• Some tumors are known to spontaneously regress and disappear. But, some tumors are known to recur or even metastasize (occasionally)
• The involvement of bone marrow can worsen the overall prognosis of the case

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

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 bone conditions:

http://www.dovemed.com/health-topics/orthopedc-disorders/