Intra-abdominal extralobar pulmonary sequestration
A separate piece of lung-like tissue. It has no normal airway connection and receives blood from a systemic artery.
Patient education · Fetal imaging
A mass near your baby's diaphragm
Intra-abdominal pulmonary sequestration or CPAM? The name matters, but the first priority is understanding the anatomy and your baby's well-being.
Plain-language guideUltrasound & DopplerPregnancy to newborn care
01Where is it?
02What supplies it?
03Is baby affected?
04What comes next?
Start with the meaning
These are developmental lung lesions, not a prenatal cancer diagnosis
Congenital pulmonary airway malformation
An area of abnormally developed airways, usually located within one of the baby's lungs.
Both begin during fetal development. Neither diagnosis means you caused the finding.
One condition · Two names
CPAM is the current name for what was called CCAM
CCAM
Congenital cystic adenomatoid malformation
→
CPAM
Congenital pulmonary airway malformation
You may see either term in older articles or medical records. They describe the same family of developmental lung lesions.
Anatomy map
The diaphragm is the first landmark
Above: the chest and lungs
Across: the diaphragm, a thin breathing muscle
Below: liver, stomach, kidneys, and adrenal regions
Why this matters
IEPS may sit below the diaphragm, often near an adrenal gland. CPAM usually develops within a lung above it.
Doppler blood-flow map
The feeding artery is the strongest prenatal clue
Usually pulmonary circulation
CPAM
The abnormal airways usually receive blood through the lung's circulation.
Systemic feeding artery
IEPS
A vessel from the aorta or one of its branches strongly supports sequestration.
Strong clue, not a promise
Some hybrid lesions share features. The prenatal diagnosis may remain provisional until newborn imaging or pathology.
Diagnostic overlap
Why can the two diagnoses look alike?
Microcystic CPAM
Tiny cysts may blend into a bright, solid-looking mass.
Ultrasound texture alone may not settle the diagnosis
IEPS
Often well-defined and solid-looking, sometimes with small cystic areas.
Overlap is real. Location, Doppler blood flow, serial imaging, and postnatal confirmation build the full answer.
What your MFM team measures
Ultrasound answers more than “What is it?”
Targeted ultrasound
+ Doppler
+ Doppler
LocationAbove or below the diaphragm?
Size & textureSolid-looking or visible cysts?
Blood supplyCan the feeding vessel be traced?
Mass effectAre organs or the heart shifted?
Normal lungHow much appears available?
Baby's conditionFluid, growth, heart function, hydrops
Two complementary tools
MRI is useful when it will answer a remaining question
Ultrasound + Doppler
- Real-time anatomy and movement
- Feeding-vessel blood flow
- Serial size and fetal well-being
+
Fetal MRI
- Relationship to the diaphragm and organs
- Lesion extent and normal lung volume
- Additional detail when ultrasound is limited
MRI complements ultrasound.
It is not automatically required, and a very small feeding vessel may still be difficult to see.
Risk is physiologic
The most important question is whether the baby is being affected
Stable
Small or steady lesion. No hydrops, severe compression, or major heart shift.
Watch closely
Growth, increasing mass effect, changing fluid, or less normal lung space.
Escalate
Hydrops, severe compression, heart dysfunction, or concern for breathing at birth.
The label guides the workup. The baby's physiology guides prenatal care.
A number in the report
CVR estimates risk; it does not decide treatment by itself
L × W × H × 0.52
Estimated lesion volume
÷
HC
Baby's head circumference
CVR = congenital pulmonary airway malformation volume ratio. Your team may use it across echogenic fetal lung lesions.
>1.6
has been associated with a higher risk of fetal hydrops. It is a risk flag, not an automatic treatment trigger.
Why the number needs context
CVR was developed mainly for fetal chest lesions. Cyst pattern, lesion location, serial change, mass effect, and the rest of the fetal examination remain essential. Evidence for predicting broader newborn outcomes uses varying thresholds.
Serial MFM assessment
Follow-up watches the trend, not a single snapshot
Define
Location, dimensions, cysts, blood supply, diaphragm, and associated anatomy.
Trend
Repeat measurements and assess the heart, fluid, growth, and signs of hydrops.
Refine
Add MRI or fetal-center review only when it can answer a remaining care question.
Plan
Choose delivery setting and newborn evaluation based on the latest findings.
No single schedule fits every pregnancy.
Your MFM team sets the interval according to gestational age, lesion size and location, serial behavior, and fetal well-being.
Escalation pathway
Fetal treatment is uncommon and depends on the complication
1
Stable fetus
Continue targeted surveillance. This is the usual pathway for a small, isolated intra-abdominal sequestration.
2
Growing chest lesion
Increase surveillance and involve a fetal center when mass effect is becoming important.
3
Specific complication
A dominant cyst, fluid collection, or selected high-risk CPAM may prompt complication-specific treatment.
4
Specialist decision
Steroids, drainage, shunting, or vascular treatment are selected tools, not routine steps.
Location changes risk.
Pleural effusion and shunting are better-established concerns for intrathoracic sequestration than for a small isolated IEPS below the diaphragm.
Birth planning
Delivery planning is based on the baby's expected needs
Stable, isolated lesion
- Usual obstetric timing may remain appropriate
- Route of delivery follows standard obstetric indications
- Newborn follow-up is arranged before discharge
Latest prenatal findings
Higher expected newborn needs
- Consider a tertiary delivery center
- Coordinate neonatology and pediatric surgery
- Prepare respiratory support and early imaging
The lesion alone does not automatically require cesarean delivery or early birth.
Newborn pathway
The diagnosis is confirmed after birth
Newborn examBreathing, oxygen, feeding, and overall stability
→
Confirm anatomyUltrasound, radiograph, CT angiography, or MRI as appropriate
→
Trace vesselsDefine the systemic feeding artery and drainage
→
Build the planPediatric surgery and pulmonary follow-up
Why image again?
Prenatal imaging is excellent for planning, but postnatal imaging can define vessels and anatomy with greater detail. It may also clarify a hybrid lesion.
Shared decision-making
Surgery is a planned decision, not always an emergency
Prompt treatment
Breathing difficulty
Feeding or circulation problems
Anatomy requiring early correction
⚖
Planned review
Baby is stable and symptom-free
Diagnosis and vessels are well defined
Observation versus elective removal discussed
The decision depends on symptoms, anatomy, feeding vessel, diagnostic confidence, local practice, and your family's discussion with the pediatric team.
Prognosis
Most isolated, stable lesions have a favorable outlook
Favorable: no hydrops
Favorable: little mass effect
Favorable: no major associated anomaly
A planned path from pregnancy to newborn care
Closer planning: rapid growth
Closer planning: reduced normal lung
Higher concern: hydrops or heart dysfunction
A reassuring course still deserves follow-up. Prenatal appearance cannot fully predict newborn symptoms or the exact final diagnosis.
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Questions to ask your MFM specialist
1Is the mass above or below the diaphragm?
2Can you see where its feeding artery comes from?
3Is it shifting the heart, normal lung, or nearby organs?
4Is there fluid buildup, heart strain, or hydrops?
5Are you measuring CVR, and what does its trend mean here?
6Would fetal MRI change our care plan?
7Where should I deliver, and does this change timing or route?
8What imaging and specialists will my baby need after birth?
A clear plan is possible even when the final label remains uncertain.
Take-home messages
What to remember
The four-question frame:
Where is it? What supplies it? Is the baby affected? What comes next?
Evidence & uncertainty
What is known, uncertain, and individualized
What is known
- Systemic arterial supply strongly supports sequestration.
- Serial imaging detects mass effect and hydrops.
- Postnatal imaging is part of confirmation.
What remains uncertain
- Exact prenatal classification of hybrid lesions
- One CVR threshold for every outcome and lesion location
- The best universal surveillance interval
What is individualized
- Whether fetal MRI adds value
- Delivery location and neonatal preparation
- Observation versus elective surgery in a stable infant
Educational disclaimer
This presentation supports informed discussion. It does not replace individualized care from your MFM, fetal center, neonatology, radiology, or pediatric surgery team.
Privacy
No patient-identifying information is used. The diagrams are educational schematics and do not represent a specific fetus or diagnostic image.
Evidence reviewed August 24, 2026OpenMFM.org
References
Evidence base
1. International Society of Ultrasound in Obstetrics and Gynecology. Patient Information: Cystic Lung Lesions. Patient leaflet.
2. Xu G, Zhou J, Zeng S, et al. Prenatal diagnosis of fetal intraabdominal extralobar pulmonary sequestration: a 12-year 3-center experience in China. Sci Rep. 2019;9:943. doi:10.1038/s41598-018-37268-1.
3. Kane SC, Ancona E, Reidy KL, et al. Utility of the CPAM-volume ratio in fetal echogenic lung lesions: a systematic review. Fetal Diagn Ther. 2020;47:171–181. PMID:31593968.
4. Zhu P, Cheng K, He M, et al. Diagnostic value of CVR for fetal hydrops due to congenital lung malformations: systematic review and meta-analysis. Orphanet J Rare Dis. 2022;17:213. doi:10.1186/s13023-022-02347-0.
5. Crombleholme TM, Coleman B, Hedrick H, et al. CCAM volume ratio predicts outcome in prenatally diagnosed CCAM. J Pediatr Surg. 2002;37:331–338. PMID:11877643.
6. Gerall CD, Chumdermpadestuk R, Jacobs S, et al. Prenatal ultrasound- and MRI-based predictors of respiratory symptoms at birth for congenital lung malformations. J Pediatr Surg. 2023;58:215–222. PMID:36220748.
7. Riley JS, Urwin JW, Oliver ER, et al. Prenatal growth characteristics and pre/postnatal management of bronchopulmonary sequestrations. J Pediatr Surg. 2018;53:265–269. Open-access article.
Terminology note. CPAM is the contemporary term for congenital cystic adenomatoid malformation (CCAM). Recommendations in this patient deck are framed as evidence-supported findings, common multidisciplinary practice, or individualized expert decisions.
Open-source patient educationLast evidence review: Aug 24, 2026