Emphysematous bleb

This code represents an emphysematous bleb, which is a small, air-filled sac within the lung tissue, typically located just beneath the visceral pleura. These blebs are a form of localized emphysema, characterized by the destruction of alveolar walls and enlargement of airspaces. They are distinct from bullae, which are generally larger.

Use this code when documentation explicitly identifies the presence of an emphysematous bleb. This often occurs in patients with chronic obstructive pulmonary disease (COPD) or other forms of emphysema, or as an incidental finding on imaging. Supporting documentation includes chest X-rays, CT scans, or surgical reports detailing the bleb's presence.

• Differentiate from emphysematous bulla (518.2), which are larger air sacs.
• Code any underlying emphysema (e.g., 492.8 for other specified emphysema) as a primary diagnosis if it is the reason for the encounter.
• Do not use this code for congenital lung cysts or other non-emphysematous air-filled lesions.