Pulmonary Sequestration

Epidemiology and Etiology:

· Intralobar sequestrations may arise from obstruction

Common sites:

· Intrapulmonary (intralobar)

· Thorax

· Diaphragm

· abdomen

Gross features:

· Lacks a connection with the tracheobronchial tree

1. If there is a connection with the alimentary trat it is a bronchopulmonary foregut malformation

· Anomalous vascular supply from the systemic circulation (often)

· Intralobar:

1. Within the normal pleural investment of the lung

2. Pleura thickened with associated adhesions

3. Cysts up to 5cm diameter

4. Fibrosis

5. Abrupt or indistinct border with normal lung

2. Extralobar:

1. Has its own pleural investment usually

Histologic features:

· Inflammation

· Interstitial fibrosis

· Dilated bronchi

1. Mucous or purulent material within

2. Alveoli filled with alveolar foamy macrophages

3. Epithelial metaplasia is common

4. Thick-walled vessels

5. Extramedullary hematopoiesis maybe

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

·

Other features:

·

References:

· Travis WDM. Non-Neoplastic Disorders of the Lower Respiratory Tract. 1st ed. American Registry of Pathology; 2002.