What is a primary characteristic of centrilobular emphysema?

Centrilobular emphysema is characterized by the dilation of the respiratory bronchioles in the upper lobes of the lungs, primarily affecting the central portions of the lobule. Unlike other forms of emphysema, centrilobular emphysema typically occurs in the upper lung zones and is often associated with smoking. The damage is localized around the central bronchioles, leading to air trapping and the characteristic abnormalities seen on imaging or during examination.

The dilation of the bronchioles is significant as it reflects the structural changes that take place in the lung due to prolonged irritant exposure, most notably from tobacco smoke. This distinctive pattern contrasts with other types of emphysema, which may affect different regions of the lungs or involve broader uniform alveolar damage.

Understanding this characteristic is crucial for identifying centrilobular emphysema when analyzing post-mortem specimens or imaging studies, as it informs the diagnosis and differentiates it from other pulmonary diseases that may present with similar symptoms.