Daily Radiology Case

Explanation

Chest radiography demonstrates a distinct visceral pleural line with absence of pulmonary markings peripheral to it, consistent with air within the pleural space separating the visceral and parietal pleura. The pathophysiology involves rupture of subpleural blebs or alveoli, allowing air to escape into the pleural cavity and abolish the normal negative intrapleural pressure required to maintain lung expansion. This results in elastic recoil of the lung toward the hilum with varying degrees of collapse depending on the volume of intrapleural air. Upright chest X-ray is highly sensitive for moderate to large pneumothoraces and remains the initial imaging modality of choice, with key findings including the pleural line, peripheral hyperlucency, deep sulcus sign in supine films, and absence of vascular markings. Recognition is critical because progression to tension pneumothorax leads to mediastinal shift, impaired venous return, and obstructive shock, requiring immediate needle decompression followed by chest tube placement.

Source: O'Donnell C, Pneumothorax due to apical blebs - surgically treated. Case study, Radiopaedia.org (Accessed on 30 Apr 2026) https://doi.org/10.53347/rID-34235

Hints

• A 55-year-old woman presents with sudden onset shortness of breath and sharp, pleuritic chest pain that began abruptly while she was at rest. She denies any recent trauma, prolonged immobilization, fever, or productive cough. She also denies prior cardiopulmonary disease and has no history of similar episodes.
• Her past medical history is unremarkable, and she does not take any medications. On examination, she is mildly tachypneic with an oxygen saturation of 92% on room air. Blood pressure is within normal limits without asymmetry, and there is no jugular venous distension or tracheal deviation. Inspection demonstrates decreased expansion of the left hemithorax, and auscultation reveals markedly diminished breath sounds on the left compared to the right. Percussion is hyperresonant over the affected lung fields.
• Initial workup shows normal cardiac biomarkers and no laboratory evidence of infection or systemic inflammation. Given the acute onset pleuritic symptoms and asymmetric pulmonary exam findings, chest imaging is obtained.
• Upright chest radiograph demonstrates a distinct, thin visceral pleural line along the lateral margin of the left lung with complete absence of pulmonary markings peripheral to this line. The left lung appears partially collapsed toward the hilum, with increased radiolucency of the surrounding pleural space. There is no evidence of mediastinal shift, diaphragmatic depression, or displacement of central thoracic structures.
• This entity has an incidence of approximately 7–18 cases per 100,000 annually and may occur spontaneously due to rupture of subpleural blebs or secondary to underlying lung disease. Small, stable cases are managed conservatively with supplemental oxygen and observation, while larger or symptomatic cases require needle aspiration or chest tube placement. Progression to tension physiology is characterized by rising intrathoracic pressure, mediastinal shift, and hemodynamic compromise, necessitating emergent decompression.