What Is Pulmonary Sequestration? Understanding This Rare Congenital Lung Condition

Pulmonary sequestration is a rare congenital anomaly that occurs during lung development, typically unrelated to genetic factors. This condition arises when a portion of the lung forms abnormally and receives its blood supply from systemic arteries—usually branches of the aorta—rather than the pulmonary circulation. Often, this abnormality is discovered incidentally during routine imaging tests such as chest X-rays or CT scans performed for unrelated reasons.

Understanding the Two Types of Pulmonary Sequestration

There are two primary classifications of pulmonary sequestration: intralobar (within the lung lobe) and extralobar (outside the lung lobe). Each type presents with distinct anatomical features and clinical implications.

Intralobar Pulmonary Sequestration

In this form, the abnormal lung tissue shares the same visceral pleura as the surrounding healthy lung tissue. It often connects to the bronchial tree, allowing air entry into the isolated segment. However, because this tissue lacks proper drainage mechanisms, it becomes prone to recurrent infections such as pneumonia or bronchitis. Patients may experience chronic cough, fever, and chest discomfort. While antibiotics can temporarily alleviate symptoms, the problem tends to recur due to persistent mucus buildup and poor clearance.

Extralobar Pulmonary Sequestration

This variant is rarer and more distinct anatomically. The sequestered lung tissue is completely enclosed by its own pleural covering, separate from the normal lung. Since it doesn't communicate with the tracheobronchial tree, it usually doesn't cause respiratory symptoms. As a result, many cases go undiagnosed until adulthood—or sometimes are only found postmortem. In some infants, extralobar sequestration may be detected prenatally via ultrasound due to visible masses in the chest cavity.

Clinical Presentation and Diagnostic Approaches

Symptoms vary widely depending on the type and size of the sequestration. Intralobar cases often present with repeated pulmonary infections, while extralobar ones may remain asymptomatic for years. When symptoms do occur, they can include chest pain, shortness of breath, and even hemoptysis (coughing up blood) in severe cases.

Diagnosis typically involves advanced imaging techniques. High-resolution CT angiography is particularly effective in identifying the aberrant systemic artery feeding the lesion—a hallmark feature of pulmonary sequestration. MRI may also be used, especially in pediatric patients, to avoid radiation exposure.

Treatment Options and Long-Term Outlook

Since pulmonary sequestration results from structural malformation during fetal development, it cannot be treated with medication alone. The gold standard for definitive management is surgical resection—removal of the non-functional lung tissue. For symptomatic patients, surgery significantly reduces the risk of recurrent infections and potential complications like abscess formation or heart strain due to abnormal blood flow.

In asymptomatic individuals, especially those diagnosed incidentally in adulthood, watchful waiting might be considered. However, given the long-term risks—including infection and possible malignant transformation—many specialists recommend prophylactic removal, particularly in younger patients.

Pulmonary sequestration, though uncommon, is an important diagnosis to consider in patients with unexplained lung infections or incidental findings on imaging. Early detection and appropriate intervention—often surgical—can lead to excellent outcomes and prevent future health complications. If you or a loved one has been diagnosed with this condition, consulting a thoracic surgeon or pulmonologist is a crucial next step toward achieving optimal lung health.