Traumatic Ulcerative Granuloma with Stromal Eosinophilia (TUGSE) Mimicking Oral Malignancy: a case series

The Great Oral Imposter: When a Scary Ulcer Turns Out to Be a Misunderstood Scab

Imagine your body is a bustling city, and the mouth is its busy downtown district. Usually, when a building gets damaged—a cut, a scrape, or a burn—the city sends in a specialized repair crew. Sometimes, this crew gets a little overzealous. They bring in so many workers that the construction site looks like a chaotic, swollen mess, even though the actual damage is just a simple scratch. In the world of medicine, this "overzealous repair crew" is often made up of white blood cells called eosinophils. These cells are famous for showing up in huge numbers when the body is fighting off parasites or dealing with allergies.

Now, picture a specific type of mouth sore called Traumatic Ulcerative Granuloma with Stromal Eosinophilia, or TUGSE for short. It's a bit of a mouthful, so let's call it the "Eosinophil Explosion." This is a harmless, non-cancerous sore that happens when the mouth tissue gets irritated—maybe by a sharp tooth, a denture, or accidentally biting your cheek. The problem is that TUGSE is a master of disguise. It doesn't look like a simple scab; it looks like a scary, hard, rolling lump that refuses to heal. Because of its scary appearance, doctors often worry it might be something much worse, like a dangerous cancer or a blood disorder. The big question for doctors is: "Is this a harmless overreaction, or is it a life-threatening invader?" Getting this wrong can lead to unnecessary panic or, worse, missing a real problem. This is where our story begins.

The Case Files: Four Stories of Deceptive Sores

This paper tells the story of four patients who walked into a dental hospital in Seoul, South Korea, between December 2025 and May 2026. Each of them had a mouth sore that looked terrifying, but the doctors had to play detective to figure out what was really going on. The researchers, led by Yong-Seung Kim, JaeHong Lee, and Mi-Hyun Seo, wanted to see if the age of the patient changed the "scary costume" the sore wore and what caused the trouble in the first place.

The Young Detectives (Cases 1, 2, and 3)
First, we meet three young patients: a 7-year-old boy, an 8-year-old boy, and a 17-year-old boy.

• The 7-year-old had a sore on his cheek that he remembered biting. It looked so hard and strange that the doctors were worried it might be lymphoma (a type of blood cancer).
• The 17-year-old, who has autism, had a sore on the floor of his mouth. Because he couldn't explain exactly what happened, and the sore had been there for months, the doctors again worried it might be a serious cancer or a lymphoma.
• The 8-year-old had a sore that stretched across his cheek and gum. Even though the doctors thought it might just be a TUGSE, they still had to be 100% sure it wasn't cancer.

In all three of these young cases, the doctors took a tiny piece of the sore (a biopsy) to look at under a microscope. The result? It was TUGSE. The "explosion" of eosinophils was there, but there was no cancer. Interestingly, when they checked the boys' blood, their eosinophil counts were completely normal. The "army" was only fighting inside the mouth, not in the bloodstream. The sores healed on their own (or with simple rinses) without coming back.

The Veteran Patient (Case 4)
Then, we meet a 68-year-old woman with a very different history. She had survived a cancer of the roof of her mouth (palatal carcinoma) years ago and had received radiation therapy to treat it. She also wore a removable partial denture for a long time. Recently, she developed a hard, indented sore on her upper gum.

• The Scary Costume: Because she had a history of cancer and radiation, and the sore was hard and didn't heal, the doctors were terrified it was the cancer coming back or a brand-new cancer.
• The Twist: They took a biopsy, and guess what? It was TUGSE! The sore was caused by the combination of her old radiation (which makes skin fragile) and her denture rubbing against it. Just like the kids, her blood test showed normal eosinophil levels, even though the sore was full of them. She healed up completely without needing cancer treatment.

The Big Takeaways: What the Paper Actually Found

The researchers found that TUGSE is a shape-shifter that changes its "scary costume" depending on who it is attacking.

• For kids and teens: The sore looks like lymphoma. The cause is usually biting the cheek, sharp teeth, or maybe even self-injury (like the teen with autism who might have been picking at his mouth).
• For older adults: The sore looks like cancer returning. The cause is usually a denture rubbing against tissue that has been weakened by past radiation therapy. This specific mix of "old radiation + denture trauma" causing TUGSE hadn't been described in detail before this paper.

The Blood Test Trap
One of the most important things the paper points out is a common mistake doctors might make. Because TUGSE is full of eosinophils, you might think a patient's blood test would show high eosinophils too. It doesn't. In all four cases, the blood tests were perfectly normal. The "army" was strictly local. The paper argues that if a doctor sees a normal blood test, they shouldn't rule out TUGSE. You can't diagnose this just by looking at the sore or checking the blood; you must take a biopsy (a tissue sample) to be sure.

What the Paper Rules Out
The paper makes it clear that you cannot rely on how the sore looks or what the blood test says to decide if it's cancer. Even though the sores looked like cancer, they weren't. The paper also suggests that while we call it "traumatic," sometimes we can't even find the specific thing that caused the injury (like in the 8-year-old where no one knew what happened). So, doctors shouldn't wait for a clear story of "I bit my cheek" before considering this diagnosis.

How Sure Are They?
The authors are very sure about the results for these four specific patients: they all had TUGSE, all had normal blood eosinophils, and all healed. However, they admit that because they only looked at four people, they can't say exactly how common this is in the whole world. They also note that they didn't do extra special stains (like CD30 testing) on the tissue because the basic microscope view was clear, but they acknowledge that in other cases, those extra tests might be needed to be absolutely certain it's not a lymphoma.

In the end, this paper is a reminder that not every scary-looking mouth sore is a monster. Sometimes, it's just a harmless, over-enthusiastic repair crew that needs a little time and a biopsy to prove it's not the enemy. Whether you are a child with a cheek bite or an adult with a denture, if a sore won't go away, the only way to know the truth is to look under the microscope.