---
title: Diagnosed with Primary Mediastinal Large B-Cell Lymphoma at 15, He Finally Achieves CMR After Multiple Treatment Setbacks
url: "https://www.yyhmedical.com/en/stories/primary-mediastinal-b-cell-lymphoma-car-t-survivor-story"
type: Article
inLanguage: en-US
disease: Primary Mediastinal Large B-Cell Lymphoma
treatment: CAR-T
datePublished: 2026-07-06
---

# Diagnosed with Primary Mediastinal Large B-Cell Lymphoma at 15, He Finally Achieves CMR After Multiple Treatment Setbacks

> After multiple lines of treatment and two rounds of CAR-T therapy, 15-year-old Xiao Chen finally achieved a complete metabolic response (CMR) after his treatment strategy was precisely reassessed and adjusted.

Summary: Xiao Chen (pseudonym) was diagnosed with stage IV primary mediastinal large B-cell lymphoma (PMBCL) at age 15. He went through chemotherapy resistance, multiple courses of immunotherapy, and two rounds of CAR-T therapy, with the disease progressing more than once. Through repeated multidisciplinary review and ongoing refinement of his treatment plan, he ultimately received immunotherapy followed by dual-target CD19/CD22 CAR-T cell therapy. On June 2, 2026, his PET/CT showed a complete metabolic response (CMR) for the first time. His story captures not only a teenager’s difficult journey through cancer treatment, but also the importance of precise reassessment, timely treatment adjustments, and long-term management in relapsed or refractory lymphoma.

**01**

Hello, I’m Xiao Chen’s mother. My son is 16 now, 175 cm tall, and has always been a bright, outgoing boy.

Before he became ill, he had just started high school and was placed in an advanced class. He loved programming. He won first prize in a provincial robotics competition and a gold medal in the middle-school division of the VEX EDR Asia Championship.

Before last October, I worked at a public-sector institution in Chengdu. We had a son and a daughter, and our life followed a steady routine. Then my son suddenly became ill, and I had to become the person holding the family together.

Xiao Chen was diagnosed with stage IV primary mediastinal large B-cell lymphoma from the start. Over the next year and a half, we went to 16 hospitals. He underwent 9 biopsies, 16 courses of chemotherapy, 7 courses of immunotherapy, 2 rounds of CAR-T therapy, 10 bone marrow aspirations, and 15 lumbar punctures.

I learned to search medical literature using Haodf.com, DeepSeek, and Yuanbao. I got used to traveling with my son between hospitals in different cities, and we went through several moments when his life was in immediate danger.

It was not until he was treated by Dr. Kai Hu at Beijing GoBroad Hospital that we finally saw a major turning point. On June 2, 2026, his PET/CT showed a complete metabolic response (CMR) for the first time.

I cried many times along the way. This was the first time I cried because I was happy.

![dce49903-88c8-4a4d-bb0d-5f160cbd1146.png](https://gaobo-byh-h5.oss-accelerate.aliyuncs.com/images/20260913/6c67a74e617c715eccf3d0557d012a06_20260913165525.png "6c67a74e617c715eccf3d0557d012a06_20260913165525.png") 

Xiao Chen recovering at home after achieving CMR

**02**

In October 2024, Xiao Chen began having recurrent fevers of around 38°C, along with fatigue, night sweats, and weight loss.

When we went to the hospital, the doctor called me into the office alone. Imaging showed a large 13.6 × 9.1 cm mass in the anterior mediastinum, enlarged lymph nodes in both hilar regions, the supraclavicular fossae, the retroperitoneum, and the abdomen, as well as multiple lesions in the liver, spleen, and both kidneys. A needle biopsy of a left cervical lymph node then confirmed primary mediastinal large B-cell lymphoma.

There was no time to process it. He was so young, and we knew treatment had to start as soon as possible.

He received his first treatment at a local hospital with DA-EPOCH-R, an intensive dose-adjusted regimen.

After chemotherapy, Xiao Chen had black stools for about two weeks, but the regimen was not adjusted. Then one day, he suddenly vomited a large amount of blood and his blood pressure dropped. He was rushed to the ICU. Standing outside the ICU, my legs were shaking.

After he left the ICU, we transferred to the hematology department of another hospital. Because he had recently experienced major bleeding, the doctors did not want to use another intensive regimen and changed treatment to R-CHOP.

But at that hospital, every cycle of chemotherapy required a new admission appointment, and a bed was not guaranteed. For a critically ill patient, that made continuity of treatment difficult. His primary doctor also changed frequently, and I was extremely anxious.

To keep his treatment on schedule, we found a way to transfer him to another department within the same hospital. For cycles 3 and 4, he received an adult CR-CHOP regimen. After four cycles, PET/CT showed disease progression.

The specialists told us chemotherapy was no longer working and suggested that we explore commercial CAR-T therapy. At the same time, they acknowledged that their department had limited experience using CAR-T in adolescents. Hearing even the specialist say that, I stood in the corridor feeling as though we had reached a dead end.

**03**

I did not have time to fall apart. I urgently asked for advice in patient support groups, took Xiao Chen’s PET/CT report, and flew to Beijing the next day. With help from a friend, I visited five hospitals in Beijing in a single day.

Every specialist recommended an adult treatment approach. But Xiao Chen was only 15.

People in the patient groups strongly urged us to try a children’s hospital and pursue a pediatric approach. I went to a pediatric specialty hospital and met with the head of its lymphoma program. The answer was clear: they could not take him. His condition was too severe and too complex, and it had moved beyond the usual scope of pediatric lymphoma treatment. We were told that by the fourth cycle of chemotherapy, the best treatment window had already been missed. Adult programs had limited experience with younger patients, while the pediatric hospital felt his disease was already too advanced. Both paths seemed closed.

On the third day, I decided to go to Guangzhou because I knew there were hospitals there with pediatric oncology departments.

**04**

The doctors at the hospital in Guangzhou took good care of Xiao Chen. But after every cycle of chemotherapy, he developed a severe infection. His immune system was extremely weak, and the crowded inpatient environment of a large public hospital, with so many patients around, was simply too much for him.

After the seventh cycle, treatment had to be interrupted for two weeks.

After the eighth cycle, the assessment showed a partial response but also new lesions. The hospital organized a multidisciplinary consultation. The conclusion was clear: the lymphoma had become resistant to chemotherapy. The team suggested considering a bispecific antibody or CAR-T therapy.

During the MDT meeting, a pathologist asked me, “Do you have any other children?” I froze.

It felt as though everyone else had given up. But I would not.

**05**

The tumor was still progressing. We could not stop.

A friend of a distant relative had received compassionate-use CAR-T therapy at a hematology hospital in Beijing. I went there looking for another chance.

The Beijing specialists developed a plan to first reduce the tumor burden with blinatumomab.

During treatment, Xiao Chen suddenly developed generalized body stiffening at around 3 a.m. It lasted about a minute. I was the only person with him, and I was terrified.

The doctors said the medication could potentially be continued, but they had not encountered this kind of reaction before and could only proceed cautiously. We had already paid RMB 50,000–60,000 out of pocket for the blinatumomab. It could not be returned or transferred to another patient.

My family said we could try again. I said no. I could not gamble with my son’s life.

**06**

After leaving that hospital, I went to two more hospitals in Guangzhou to look for a CAR-T option. At one cancer hospital, patients aged 15 and older who wanted commercial CAR-T therapy had to go through the hospital’s ethics review process. We did not have time to wait.

At another hospital, the treatment was not controlling the tumor well, and Xiao Chen developed side effects including a rash and hypoglycemia. His attending doctor told us directly that they had not seen a similar situation and could only try to manage it step by step. I could not let Xiao Chen keep feeling like a test case.

**07**

We returned to Beijing, where I found a leading pediatric lymphoma specialist. By then, Xiao Chen could no longer lie flat because he was short of breath. Even for an MRI, he had to be positioned on his side.

After a detailed assessment, the specialist developed a new plan. After several courses of treatment, the tumor was finally brought under control and began to shrink. For the first time, I saw hope.

He then received three sessions of radiotherapy, with a plan to infuse CD19 CAR-T cells afterward. But he developed a fever after radiotherapy. The CAR-T infusion was given a week later, but the cells did not expand well, and the disease progressed again.

Xiao Chen did not know. He happily told me, “Mom, once I’m discharged, I’ll take online classes at home, and on weekends I want to go out with my classmates and just hang out and talk.” I could not hold it together. I hid in the bathroom and cried, then went outside and let the winter wind in Beijing dry my tears.

He was at an age when life should have been opening up, yet he had already been through so much.

He did not know that after so many rounds of chemotherapy, radiotherapy, and CAR-T therapy, the disease had progressed again. I could not imagine how hopeless he would have felt if he had known.

Three children with lymphoma in the room next door passed away one after another. I did not even have time to break down.

**08**

So I started searching for a way forward again.

I went to other major general hospitals in Beijing to seek expert opinions, doing everything I could to get appointments with top national specialists, including academicians. Online, I read other patients’ experiences on Haodf.com and used DeepSeek and Yuanbao to search and analyze medical literature.

I gradually began to suspect that Xiao Chen’s disease might need to be treated specifically as primary mediastinal large B-cell lymphoma, and that adult and pediatric treatment strategies could be very different. I raised this with his specialist twice. She also consulted a pathologist, who felt the diagnosis was not primary mediastinal lymphoma and continued to favor a diffuse large B-cell lymphoma treatment approach.

To her credit, the specialist was very open to discussion and quickly organized a multidisciplinary consultation. During the meeting, I heard Dr. Kai Hu from Beijing GoBroad Hospital propose a new pola-based regimen. It was exactly in line with the direction I had found in the cases I had been reading.

Dr. Hu’s comments at the meeting stayed with me. He was not the kind of doctor who simply gave a conclusion. He explained the reasoning—why the previous direction might not have been right, and why a pola-based approach might be more suitable for Xiao Chen. His logic was very clear.

The hospital adopted Dr. Hu’s recommendation and gave two cycles of the new pola-based regimen. The tumor came under control and shrank.

It felt like sunlight finally breaking through a crack. But by then, Xiao Chen’s body was exhausted.

After so much chemotherapy, he was in very poor physical condition. Drug side effects had accumulated, infections kept recurring, and for more than ten days he was unable to pass gas on his own.

I learned that Dr. Hu had managed more than 2,000 complex lymphoma cases and had extensive experience. I decided to transfer Xiao Chen to Beijing GoBroad Hospital to be treated by Dr. Hu.

**09**

Dr. Hu’s team developed a clear strategy: four cycles of immunotherapy followed by dual-target CD19/CD22 CAR-T cell therapy. Each step was carefully paced. Xiao Chen did not develop severe cytokine release syndrome (CRS), there were no uncontrollable complications, and his infections were brought under control.

Little by little, Xiao Chen began to recover. On June 2, 2026, a follow-up PET/CT showed a complete metabolic response (CMR), and circulating tumor DNA (ctDNA) was negative.

Looking back, achieving CMR depended on making the right decisions at key points and continuing to refine the treatment strategy. Dr. Hu played a critical role in the timing and sequencing of therapy—knowing when immunotherapy was needed to reduce tumor burden, when it was time to move into CAR-T therapy, and when to select the treatment targets. Every step was based on ongoing reassessment of Xiao Chen’s condition.

The entire team also worked with strong coordination and execution. From physicians and nurses to the inpatient environment and infection control, every part of the care mattered. With a complex, difficult-to-treat lymphoma, you need more than one experienced specialist—you need an entire team that can work together under pressure.

**10**

My son has changed a lot over the past year and a half.

Before he became ill, he was cheerful and outgoing. He smiled a lot, loved basketball, and had many friends. Now he talks less and is often quiet. I understand. Anyone who has spent so long in a hospital bed and gone through so many rounds of chemotherapy, bone marrow aspirations, and lumbar punctures would have difficult days.

But he finds his own way to make peace with what he has been through.

I told him, “What you’ve experienced is something most of your classmates may never face in their entire lives. It is a different kind of life experience. In the future, you might even consider studying integrative medicine or biomedical science. What you’ve lived through has already given you a very personal understanding of healthcare.” I wanted him to know that this year and a half had not simply been lost time.

His younger sister often sends me messages on her smartwatch: “Mom, how is my brother? When is he coming home?” Every time, all I could say was, “Soon.”

Now, finally, he can go home.

If Xiao Chen continues to recover, I want to do something for other patients with blood diseases when we get home. So many people helped us along the way—strangers in patient support groups, doctors who replied to my messages late at night, relatives and friends who helped us contact hospitals. I want to pay that kindness forward.

**11**

Finally, I want to share a few words with patients and families who are still in the middle of treatment:

First, hold on to hope. Refractory disease, relapse, infection, or blood counts hitting their lowest point—none of it is easy. As long as you do not give up, there may still be choices and possibilities.

Second, find a medical team you trust and work closely with them. Trust can make a real difference in how treatment moves forward. At the same time, stay informed: look for relevant treatment experiences and published cases, and share useful information with your care team.

Third, take infection prevention and supportive care seriously. When the immune system is weak, infection can be one of the greatest dangers. Every mask, every careful hand wash, and every clean, nutritious meal is part of the defense.

And remember: you are not fighting alone. Family support gives strength, encouragement from other patients can be a light in the dark, and the medical team is there to protect and support you. Most importantly, be kind to yourself and take care of yourself too.

One more lesson I learned the hard way: make sure your family has adequate critical illness insurance. A relatively small premium can make a major difference when serious illness strikes.

I wish every patient a smooth recovery.

> This content is published with the authorization of the patient and their family, intended solely to share real experiences and health knowledge. It does not constitute a recommendation of any treatment plan or medical diagnostic advice. For specific treatment, please follow the guidance of a professional physician.

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