Chinese Doctors Report Fetal Lung Lesion Ablation in August Case

Chinese doctors have used a minimally invasive microwave procedure to shrink a potentially life-threatening lung lesion in a baby while the fetus was still inside the mother’s womb. The treatment was performed at 22 weeks of pregnancy using a thin needle guided by real-time ultrasound, avoiding open fetal surgery.

The case involved congenital pulmonary airway malformation (CPAM), a developmental abnormality rather than lung cancer. The lesion had grown to about 5 centimetres and was compressing the baby’s heart and lungs, while fluid had also accumulated in the abdomen. The original clinical letter indexed by PubMed was published on August 20, 2026. News reports brought it renewed attention on October 6, but the procedure is not a new October event. A single case cannot establish treatment safety or effectiveness.

Key takeaways

• Doctors from Shenzhen Baoan Women’s and Children’s Hospital and The Chinese University of Hong Kong treated the fetus at 22 weeks’ gestation.
• The lung lesion measured about 5 cm and was causing severe compression inside the fetal chest.
• The fetus had also developed ascites, or abnormal fluid accumulation in the abdomen.
• Doctors inserted a thin needle through the mother’s abdomen and uterus into the fetal lesion.
• Microwave energy was delivered through the needle for about two minutes.
• The lesion had shrunk significantly within three days.
• The abdominal fluid had also disappeared.
• The baby was delivered by Caesarean section at 37 weeks, weighing about 2.9 kg.
• At four months, the baby was reported to have no symptoms and had not required another operation.
• The doctors described the procedure as a milestone, but stressed that one case is not enough to establish safety or effectiveness.

What happened to the baby?

Doctors detected the abnormality during pregnancy in a 40-year-old woman.

By 22 weeks, imaging showed that the lesion had grown to approximately 5 cm and occupied much of the right side of the fetal chest. Its size was creating pressure on the baby’s heart and lungs.

The fetus had also developed ascites, a condition in which fluid accumulates in the abdominal cavity. In severe fetal lung lesions, pressure inside the chest can interfere with normal circulation and contribute to serious complications.

The medical team therefore faced a difficult situation: the lesion needed to be reduced while the fetus was still too early in pregnancy for delivery to be a realistic solution.

The doctors decided to attempt a minimally invasive procedure rather than open fetal surgery.

The condition was CPAM, not a conventional cancer

The term “lung tumour” used in news reports can be misleading.

The baby did not have a conventional lung cancer. The condition was congenital pulmonary airway malformation, or CPAM, a developmental abnormality involving abnormal lung tissue.

CPAM can range from small lesions that cause few problems to large, rapidly growing masses that can compress the heart and lungs.

Medical literature describes CPAM as a cystic mass made up of abnormal pulmonary tissue. Larger lesions can be associated with fetal fluid accumulation and other complications.

This distinction is important because the Chinese doctors were not treating a malignant cancer with microwave energy. They were destroying abnormal developmental tissue that was threatening the fetus because of its size and location.

Why conventional treatment was difficult

Doctors already have several ways of managing severe fetal lung lesions, but the appropriate approach depends on the lesion’s size, structure and effect on the fetus.

Large fluid-filled cysts can sometimes be drained, including through a procedure in which a tube is placed to allow fluid to escape. Maternal corticosteroids can also be used for certain large CPAMs, particularly microcystic lesions.

In extreme cases, open fetal surgery can be considered at specialist centres.

The lesion in this case presented a different problem.

According to the case reports, it consisted of numerous small cysts and did not have a central blood vessel that could be targeted. That made some established fetal interventions unsuitable.

The medical team therefore looked for a way to destroy the abnormal tissue directly while keeping the intervention as limited as possible.

How microwave ablation worked

The procedure used a technique called microwave ablation.

Doctors first used high-resolution ultrasound to identify the fetal lesion and continuously monitor the position of the needle.

A thin needle was then guided through the mother’s abdominal wall and uterus and into the abnormal tissue in the baby’s chest.

Microwave energy was delivered through the needle.

The energy causes molecules within the tissue to move rapidly, producing heat. That heat destroys the targeted abnormal tissue from the inside.

The heating stage lasted approximately two minutes in the reported case. Doctors monitored the procedure with ultrasound to reduce the risk of damaging surrounding structures.

The approach is considerably different from open fetal surgery.

Instead of opening the uterus and physically removing the lesion, doctors attempted to reduce its volume by destroying tissue through a small percutaneous access route.

The response came within days

The procedure produced a rapid change.

Three days after microwave ablation, the lesion had shrunk significantly, according to the published case reports.

The fluid that had accumulated in the fetus’s abdomen had also disappeared.

That improvement allowed the pregnancy to continue rather than requiring immediate delivery or a more extensive fetal operation.

The pregnancy subsequently progressed to 37 weeks.

The baby was delivered by Caesarean section at approximately 2.9 kg.

The newborn received an Apgar score of 10 and was reported to be in good condition. At four months of age, the baby remained symptom-free and had not required another operation.

Why treating the fetus before birth matters

Fetal medicine has increasingly moved toward treating certain serious conditions before birth rather than simply waiting until delivery.

The logic is straightforward.

If a rapidly growing lesion is already compressing a fetus’s heart and lungs, allowing the pregnancy to continue without intervention may carry significant risks.

At the same time, operating directly on a fetus creates its own risks for both the fetus and the mother.

That makes minimally invasive fetal procedures particularly attractive when they can address the underlying problem without requiring open surgery.

The new case demonstrates one possible way to achieve that balance.

It does not, however, establish that microwave ablation is now a standard treatment for CPAM.

This is reportedly the first fetal CPAM microwave-ablation case

The published case is particularly significant because the authors describe it as the first reported use of microwave ablation for a fetal microcystic CPAM.

The report was authored by researchers and clinicians from Shenzhen Baoan Women’s and Children’s Hospital and The Chinese University of Hong Kong. It was published in Ultrasound in Obstetrics & Gynecology, the official journal of the International Society of Ultrasound in Obstetrics and Gynecology.

The journal publication provides a peer-reviewed record of the procedure.

However, the publication is a case report/letter, not a large clinical trial.

That distinction is crucial.

A successful outcome in one pregnancy demonstrates that a procedure can be performed and may work under particular circumstances. It cannot establish how often the procedure will succeed, which patients are appropriate candidates or what rare complications could emerge when the technique is used more widely.

How common is CPAM?

CPAM is uncommon.

News reports associated with the case cite an estimated occurrence of roughly one in 25,000 to 35,000 pregnancies.

Other medical literature reports different incidence estimates depending on whether researchers count only symptomatic cases, live births or prenatally detected lung lesions.

Most CPAM cases do not result in the kind of severe fetal compression seen in this case.

The problem becomes particularly serious when a lesion grows rapidly and interferes with the normal position or function of the heart and lungs.

The Society for Maternal-Fetal Medicine notes that CPAM is among the pulmonary lesions associated with non-immune hydrops and that the risk increases with larger lesions. Current management can include maternal corticosteroids and, for selected large cystic lesions, procedures such as cyst aspiration or thoracoamniotic shunting.

How this differs from open fetal surgery

Open fetal surgery is substantially more invasive.

In procedures such as fetal lobectomy, surgeons may open the uterus and operate directly on the fetus to remove a lung lesion.

That can be lifesaving in carefully selected circumstances, but it carries significant maternal and fetal risks.

The microwave procedure attempts to avoid that level of intervention.

The needle passes through the mother’s abdomen and uterus, reaches the lesion and delivers energy directly into the abnormal tissue.

There is therefore no need to open the uterus surgically for the ablation itself.

That does not mean the procedure is risk-free.

A needle still has to pass through maternal and fetal structures, and microwave energy must be delivered precisely enough to destroy abnormal tissue without causing unacceptable injury to the surrounding organs.

Why ultrasound guidance was critical

The success of the procedure depended heavily on imaging.

The doctors used real-time, high-resolution ultrasound to locate the lesion and guide the needle.

That is particularly important in fetal procedures because the target is extremely small and constantly affected by fetal movement.

The medical team also needed to account for the proximity of the heart, lungs and other structures.

Ultrasound allowed the clinicians to visualize the needle’s position and monitor the procedure while the microwave energy was delivered.

This combination of advanced imaging and minimally invasive intervention is one of the important developments highlighted by the case.

The biggest limitation: one successful case

The most important caveat is also the simplest.

This was one case.

The doctors themselves cautioned that the safety and effectiveness of the technique cannot be established from a single procedure.

A larger number of pregnancies would need to be studied to determine whether the treatment is reproducible and whether complications emerge that are not visible in a single successful case.

Researchers would also need to determine which types of CPAM are suitable for microwave ablation.

The technique may not work equally well for every lesion.

The size, location, tissue structure, vascular supply, gestational age and condition of the fetus could all influence whether the procedure is appropriate.

What happens after birth?

The successful prenatal treatment does not necessarily mean the underlying lung abnormality has permanently disappeared.

Children with prenatally diagnosed lung lesions can require postnatal imaging and follow-up even when the lesion appears to have regressed during pregnancy.

Medical literature recommends postnatal evaluation because a lesion can remain present even when it is difficult to detect on late-pregnancy ultrasound. Some children with persistent lesions may eventually require surgery depending on symptoms and anatomy.

In the reported case, the baby had no symptoms at four months and did not require another operation.

Longer-term follow-up will nevertheless be important.

Could microwave ablation become a standard fetal treatment?

It is too early to say.

The case provides evidence that the technique is technically possible and can produce a rapid reduction in a severe fetal lung lesion.

That is an important first step.

But medical treatments become standard only after evidence accumulates across more patients and different clinical settings.

Future research would need to examine safety, fetal survival, pregnancy outcomes, neurological and developmental outcomes, lung function and the rate at which additional procedures are needed after birth.

Researchers would also need to compare microwave ablation with existing treatments.

The objective would not simply be to show that the new procedure works. It would need to demonstrate when it works better, or with fewer risks, than the alternatives.

The Bigger Picture

The significance of the Chinese case lies less in the headline of “shrinking a tumour in the womb” and more in what it demonstrates about the direction of fetal medicine.

Doctors are increasingly able to diagnose serious fetal abnormalities early in pregnancy and intervene while the fetus remains inside the uterus.

In this case, the team used imaging, a very small access route and targeted thermal energy to reduce a lesion that was threatening the baby’s heart and lungs.

If the approach proves safe and reproducible, it could eventually add another option for a small group of pregnancies involving severe CPAM.

But the distinction between a promising first case and an established medical treatment is essential. The published evidence currently supports the former, not the latter.

Looking Ahead

The next step will be additional clinical experience and carefully documented follow-up. Researchers will need to establish which fetal lung lesions are suitable for microwave ablation, what energy settings provide the best balance between tissue destruction and safety, and how babies treated before birth develop over the longer term.

For now, the case represents an important proof of concept rather than a new routine treatment. Its biggest contribution may be showing that severe fetal lung lesions can potentially be treated through a minimally invasive, image-guided approach at a stage of pregnancy when conventional surgery would carry substantial challenges.

FAQs

What condition did the baby have?

The baby had congenital pulmonary airway malformation (CPAM), a developmental abnormality in which abnormal lung tissue forms during fetal development. It was not conventional lung cancer.

How did doctors shrink the fetal lung lesion?

Doctors inserted a thin needle through the mother’s abdomen and uterus and into the fetal lesion under ultrasound guidance. Microwave energy was then delivered through the needle to heat and destroy abnormal tissue.

Was the baby born healthy?

The baby was delivered by Caesarean section at 37 weeks, weighing about 2.9 kg. Reports said the infant was in good condition and remained symptom-free at four months without needing another operation.

Is fetal microwave ablation now a standard treatment?

No. The procedure is a promising case report, but one successful case cannot establish safety or effectiveness. More research and clinical experience are needed before it could become a standard treatment for severe CPAM.

Is CPAM cancer?

No. CPAM is a congenital developmental abnormality of the lung. It can form a mass-like lesion and, in severe cases, threaten the fetus by compressing the heart and lungs, but it is not the same as a malignant lung cancer.