Inflammatory myofibroblastic tumor
Inflammatory myofibroblastic tumor
Also known as:IMT, inflammatory pseudotumor-like tumor, China Second Rare Disease Catalog item 42
Inflammatory myofibroblastic tumor is a rare intermediate soft tissue tumor that can arise in the lung, abdomen, pelvis, bladder, head and neck, or other sites, and often needs pathology plus ALK and other molecular testing to distinguish it from inflammation, infection, and other tumors.
Start Here
A quick guide to the next step: which department to start with, what to prepare, and what to ask.
An unexplained mass, persistent inflammatory signs with a solid lesion on imaging, or pathology suggesting IMT should be reviewed by oncology, the relevant surgical team, and pathology/molecular diagnostics.
IMT is made of myofibroblast-like tumor cells mixed with inflammatory cells. Many grow locally, while some recur, invade, or rarely metastasize. ALK, ROS1, NTRK, and other fusions can guide therapy.
Complete surgical removal is central when feasible. Unresectable, recurrent, metastatic, or ALK-positive disease may lead to discussion of ALK inhibitors or other targeted therapy, systemic treatment, or trials.
IMT is usually not inherited, so relatives usually do not need screening. Molecular testing is mainly for diagnosis and targeted-treatment planning.
Fever, anemia, high inflammatory markers, or local pain can make IMT look like infection, an inflammatory mass, or a benign tumor for a long time.
This page helps patients and families organize care leads. It does not replace a clinician’s diagnosis or treatment plan. For testing, medication, referrals, emergency care, and support applications, follow qualified clinicians, medical institutions, support organizations, and official sources.
Diagnosis Path
Organized around the practical patient journey: identify clues, avoid common delays, then prepare for care.
When to Suspect It
- Imaging shows a lung, abdominal, pelvic, bladder, head/neck, or soft tissue mass that does not resolve with routine infection treatment.
- A mass is accompanied by recurrent fever, weight loss, anemia, high platelets, or high CRP/ESR.
- A pathology report mentions IMT, spindle cell lesion, ALK positivity, or inflammatory pseudotumor-like features.
- A previously treated lesion recurs locally or new lesions appear on imaging.
Common Wrong Turns
- Repeated antibiotics for an inflammatory mass without tissue diagnosis.
- No expert pathology review or immunohistochemistry/molecular testing when pathology is unusual.
- Local treatment without asking about ALK, ROS1, NTRK, or other targetable tests.
- Assuming no follow-up is needed after resection.
Departments to Start With
- Medical oncology
- Relevant surgical specialty
- Pathology/molecular diagnostics
- Radiology review
Before the Visit
- Bring all CT, MRI, ultrasound, or PET-CT images and reports.
- Bring biopsy/surgical pathology, immunohistochemistry, molecular testing, and slide/block information.
- Record fever, pain, weight change, anemia, inflammatory markers, and response to antibiotics.
- Collect operative notes, margin status, recurrence timeline, and prior tumor treatment.
Tests to Ask About
- Contrast CT/MRI of the lesion to define extent, adjacent organs, and resectability.
- Pathology review plus ALK immunohistochemistry, with NGS or fusion testing when needed.
- Whole-body or site-specific staging and recurrence assessment.
- Whether complete resection, observation, targeted therapy, or clinical trial fits the case.
Questions for the Doctor
- Can my tumor be completely removed, and how does margin status affect recurrence risk?
- Have ALK, ROS1, NTRK, or related tests been done, and can they guide treatment?
- If we observe for now, what are the risks and imaging intervals?
- For recurrence or unresectable disease, what targeted medicines, systemic therapies, or trials are options?
Basic Information
Medical Notes
More complete medical explanations are kept here for discussion with clinicians.
Symptoms
Symptoms depend on location. Lung lesions may cause cough, chest pain, or be found incidentally. Abdominal or pelvic tumors may cause pain, bloating, or bowel obstruction-like symptoms. Bladder tumors may cause blood in urine or urinary symptoms. Some patients have fever, fatigue, weight loss, anemia, high platelets, or high inflammatory markers.
Some people have few symptoms and are diagnosed after imaging finds a mass. Local recurrence can occur, and a small subset behaves more aggressively.
Diagnosis
Diagnosis depends on pathology, often supported by immunohistochemistry and molecular testing. ALK positivity supports the diagnosis and can guide targeted therapy, but ALK-negative tumors can still be IMT, so clinicians may test ROS1, NTRK, RET, or other fusions.
Mimics include infectious inflammatory masses, inflammatory pseudotumor, IgG4-related disease, smooth muscle tumors, gastrointestinal stromal tumor, sarcoma, lymphoma, and metastatic tumor. Complex cases should have expert pathology review.
Treatment
When localized IMT can be completely removed, surgery is usually preferred. Observation, repeat surgery, or additional treatment depends on location, margins, recurrence risk, and pathology/molecular findings.
For unresectable, recurrent, or metastatic IMT, ALK-positive tumors may be treated with ALK inhibitors; other fusion-positive tumors may have matching targeted options. Multidisciplinary planning is important.
Long-term Care
Follow-up tracks local imaging, symptoms, inflammatory markers, post-surgical function, and medication side effects. Intervals depend on site, completeness of resection, molecular findings, and recurrence risk.
Fertility and Family
IMT is usually not managed as an inherited disease. Young patients who need long-term targeted therapy, chemotherapy, or pelvic surgery/radiation should ask about fertility preservation, pregnancy safety, and contraception.
When to Seek Urgent Care
Bowel obstruction-like pain and vomiting, coughing blood, severe blood in urine, shortness of breath, persistent high fever, severe pain, postoperative infection, or serious targeted-therapy side effects require urgent care.
Prognosis
Many localized tumors can be controlled with proper treatment, but recurrence can occur and a minority behave aggressively, so follow-up depends on margins and molecular findings.