Inflammatory Myofibroblastic Tumor, from the CureRays guide library.

Inflammatory myofibroblastic tumor is a rare borderline tumor of children and young adults, often driven by an ALK gene change, that is usually cured by surgery and increasingly treated with targeted pills when it cannot be fully removed.

What it is.

Inflammatory myofibroblastic tumor (IMT) is a rare growth made of spindle-shaped 'myofibroblast' cells mixed with inflammatory immune cells. It is considered a borderline or low-grade cancer: it can grow into nearby tissue and occasionally spread, but it usually behaves in a much less aggressive way than typical cancers. It occurs most often in children, teenagers, and young adults, and can arise almost anywhere — the lung, abdomen, pelvis, and the soft tissues are common sites. Many IMTs are driven by a rearrangement of the ALK gene (or, less often, ROS1 or other genes), which produces an abnormal protein that fuels the tumor's growth. This discovery is important because it means many IMTs can be treated with targeted pills that block ALK, especially when surgery alone is not enough. Most IMTs are cured by complete surgical removal; radiation and targeted therapy are used for tumors that cannot be fully removed or that come back.

How radiation treats it.

Radiation damages the DNA inside tumor cells so they can no longer divide and survive, while healthy cells repair themselves more effectively. For inflammatory myofibroblastic tumor, radiation is used selectively — to treat tumors that cannot be fully removed, to clean up close surgical margins, or to control a tumor in a sensitive location. It is delivered as a series of short, painless daily sessions, uses no radioactive implants, and leaves no radioactivity in your body, so you remain safe to be around family and children. Because many of these tumors affect children, teams plan radiation carefully to protect growing tissue and often weigh targeted pills as an alternative.

The ways we can treat it.

External-beam radiation (IMRT). Computer-shaped beams treat the tumor or tumor bed while sparing nearby organs — useful when surgery would be disfiguring or incomplete.

Stereotactic radiation (SBRT/SRS). Focused, high-dose radiation can precisely treat a tumor in a difficult location or a single site of recurrence while protecting surrounding tissue.

Radiation with targeted therapy. Radiation may be combined with or follow ALK-targeted pills to consolidate the response in tumors that cannot be removed.

Questions we hear often.

Is this really a cancer? IMT sits in a borderline category. It can grow into nearby tissue and, rarely, spread, so it is taken seriously and treated, but most IMTs behave far less aggressively than typical cancers and are cured by surgery.

What does 'ALK-positive' mean for my treatment? It means the tumor carries an ALK gene change that drives its growth. That is good news for treatment, because targeted pills that block ALK can shrink these tumors dramatically — a powerful option when surgery alone isn't enough.

Will it come back after surgery? Most completely removed IMTs do not return, but because they can recur locally, your team will follow you with periodic exams and imaging. If a tumor does come back, options include repeat surgery, targeted therapy, and radiation.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.