Subpleural

Subpleural is an anatomical descriptor used to indicate tissue or lesions located beneath the pleural membranes that line the chest wall and cover the lungs. In practice, the subpleural region refers to the outer portion of the lung parenchyma adjacent to the pleura, typically extending to a short distance from the pleural surface. The term is commonly used in imaging and pathology to describe where a finding is located relative to the pleura.

In radiology, subpleural features are used to describe the distribution of abnormalities on chest radiographs or CT scans. Subpleural nodules, subpleural lines, and subpleural reticulation are terms that convey peripheral involvement near the lung surface. Subpleural fibrosis or honeycombing denotes fibrotic changes concentrated near the pleura and is often seen in certain interstitial lung diseases. Subpleural blebs or bullae are small air-filled spaces that occur close to the lung surface and can be associated with emphysema.

The term does not denote a distinct anatomical space but rather a location relative to the pleural membranes. Recognizing subpleural involvement can aid in diagnosing and characterizing diseases, as some conditions show a peripheral or subpleural predominance. Subpleural pathology can arise from inflammatory, infectious, fibrotic, or neoplastic processes and may influence assessment of disease extent and prognosis in respiratory care.