Lung hernia: a strange condition

A 55-year-old man with a history of chronic alcohol intake, smoking, obesity, and obstructive sleep apnea syndrome. Right rib pain after trauma a few months ago, suspected rib fracture. A cleft is palpated between the last right ribs.

Chest X-ray (figure 1): Soft tissue enlargement in the right inferolateral region with well-defined and air-density structure at the ipsilateral base, which seems to be continued with the lung.

Chest CT: Mediastinal and lung windows (figures 2a and 2b): rupture of the intercostal muscles located between the 8^th and 9^th right costal arches, with herniation of lung tissue through them.

Findings are consistent with pulmonary hernia.

Background

Pulmonary hernia is an abnormal protrusion of the lung parenchyma through a defect in the thoracic cavity. It is a rare condition, about 300 cases have been described in the literature[1]. Its pathophysiology is related to the sudden increase in intrathoracic pressure, such as coughing, sneezing, vomiting or weight lifting[2]. Risk factors are rib fracture, trauma, thoracic surgery, COPD, infections, neoplasms, obesity and taking steroids[3].

Clinical Perspective

It can be asymptomatic, manifests as acute pain or a soft mass that increases with Valsalva manoeuvres [2]. It can be complicated by incarceration, hemoptysis, or infection[4].

Imaging Perspective

Its diagnosis is mainly clinical and is complemented with chest radiography and CT. An expiratory and oblique chest X-ray is recommended[3]. It is described based on the Morel-Lavallee classification and is based on the location and aetiology of pulmonary hernias: location (diaphragmatic, intercostal, or cervical) and aetiology (congenital or acquired)[1].

Outcome

Observation or surgery are the treatment options. Surgical intervention is performed when it is large, symptomatic or becomes incarcerated. CT helps to determine the location, size and herniated parenchyma, prior to surgical treatment[2].

Take-Home Message/Teaching Points

Pulmonary hernias are protrusions of the lungs. They are classified according to their location and aetiology. They are associated with rib fractures and increases in intrathoracic pressure. Helps to characterize it prior to surgery.

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