What is pulmonary capillary haemangiomatosis?
In pulmonary capillary haemangiomatosis (PCH), thin-walled capillaries grow in excess through the walls of the air sacs, around airways and into the walls of veins and arteries. These extra vessels obstruct blood flow and raise the pressure in the lung circulation, placing strain on the right side of the heart.
PCH and pulmonary veno-occlusive disease (PVOD) share the same genetic cause, very similar scans and the same response to treatment, and pathologists often find both patterns in the same lung. Current ESC/ERS pulmonary hypertension guidelines therefore group them together as a single PVOD/PCH entity within pulmonary arterial hypertension. It is ultra-rare, with only a few people per million affected.
Symptoms
- Progressive breathlessness, first on exertion and later with daily activities.
- Fatigue and reduced exercise tolerance.
- Coughing up blood (haemoptysis): more frequent in PCH than in most other forms of pulmonary hypertension, because the fragile capillaries can bleed.
- Chest pain, dizziness or fainting on exertion.
- Leg swelling as the right heart weakens.
Oxygen levels tend to fall noticeably on walking. Some people have recurrent pleural effusions.
Causes and risk factors
The most important known cause is inherited mutation in both copies of the EIF2AK4 gene, the same gene responsible for heritable PVOD. This form may affect several siblings and is more likely when parents are blood relatives. Other cases occur without a family history and the trigger is often unknown. Associations with connective tissue disease, previous chemotherapy and solvent exposure have been described in the overlapping PVOD spectrum.
How PCH is diagnosed
A definite diagnosis has historically required lung tissue, but surgical biopsy is dangerous in pulmonary hypertension and is generally avoided. A combination of non-invasive and catheter tests is used instead.
| Test | What it shows |
|---|---|
| Echocardiography | Raised pulmonary pressure and right heart enlargement |
| Right heart catheterisation | Pre-capillary pulmonary hypertension with a normal wedge pressure |
| High-resolution CT chest | Diffuse, ill-defined centrilobular nodules, sometimes with septal thickening and enlarged lymph nodes |
| Lung function tests | A severely reduced gas transfer (DLCO) |
| Genetic testing | EIF2AK4 mutations that support the diagnosis without biopsy |
| Bronchoalveolar lavage (selected cases) | Signs of hidden bleeding into the lungs |
The nodular CT pattern can be confused with infection, including miliary tuberculosis, or with hypersensitivity pneumonitis, so it is interpreted together with the pressure findings.
Treatment
Pulmonary hypertension medicines
Endothelin receptor antagonists, phosphodiesterase-5 inhibitors and prostacyclin pathway drugs can provoke pulmonary oedema in PCH because they increase flow into an obstructed capillary bed. If used, they are introduced cautiously, one at a time, with close observation in a specialist setting.
Supportive treatment
Oxygen therapy, diuretics for fluid retention and careful management of haemoptysis are central. Anticoagulants are generally avoided or used with great caution because of the bleeding risk.
Other approaches
Medicines that target abnormal blood vessel growth have been tried in individual patients, but evidence is limited and they are not standard treatment.
Lung transplantation
Lung transplantation is the only definitive treatment. Early referral to a transplant centre is recommended once the diagnosis is suspected, with coordination between respiratory medicine, cardiology and the transplant team.
Outlook and follow-up
PCH usually progresses over a few years, and response to medicines is limited, which is why timely transplant assessment matters. Follow-up includes walk tests, oxygen assessment, echocardiography and blood markers of heart strain. Family members of patients with EIF2AK4 mutations can be offered genetic counselling. Patients in Hyderabad can be assessed at Apollo Hospitals, Financial District, with shared care alongside cardiology and transplant services.
Living with PCH
Day-to-day activity is encouraged within comfortable limits, avoiding heavy straining or lifting. Flying may require supplemental oxygen, and high-altitude travel is best avoided. Pregnancy carries a very high risk in pulmonary hypertension, so reliable contraception is discussed. Any new medicine, including over-the-counter remedies, should be checked for effects on bleeding or blood pressure.
When to seek urgent care
Go to the emergency department if you cough up more than a small streak of blood, become breathless at rest, faint, develop chest pain, or produce pink frothy sputum, especially after a change in pulmonary hypertension medicine.
Frequently asked questions
Are PCH and PVOD the same disease?
They are now considered closely related and are grouped together in guidelines. They share the same gene, similar scans and the same treatment approach, and both patterns are often found in the same lung.
Why is coughing up blood common in PCH?
The abnormal capillaries are thin-walled and fragile, so they can bleed into the air spaces. Any significant blood in the sputum should be assessed urgently.
Can PCH be mistaken for tuberculosis?
Yes. The small nodules on CT can resemble miliary tuberculosis or other infections. The combination with high lung pressures and very low gas transfer points towards PCH.
Will standard pulmonary hypertension tablets help?
They may help some patients but can cause dangerous fluid build-up in the lungs. They are only started cautiously under specialist supervision.
Is lung transplantation necessary?
Transplantation is the only curative option. Early referral allows assessment before the illness becomes too advanced.
Can I travel by air with PCH?
Many patients can fly, but the lower cabin oxygen level may make breathlessness worse. An assessment before travel determines whether in-flight oxygen is needed.
Related conditions and procedures
Consult Dr. Gogineni Ratnakara Rao
Apollo Hospitals, Financial District: Monday to Saturday, 8:30 AM to 5:00 PM. Anything in Lung Clinic, Chanda Nagar: Monday to Saturday (Thursday closed), 6:00 PM to 9:00 PM.