A pneumatocele is a cavity in the

lung parenchyma file:emphysema, bullous, subpleural and honeycomb fibrosis (4563270966).jpg, upright=1.6, Lung parenchyma showing damage due to large subpleural Focal lung pneumatosis, bullae. Parenchyma () is the bulk of functional substance in an animal org ...

filled with air that may result from pulmonary trauma during

mechanical ventilation Mechanical ventilation or assisted ventilation is the Medicine, medical term for using a ventilator, ventilator machine to fully or partially provide artificial ventilation. Mechanical ventilation helps move air into and out of the lungs, wit ...

. Gas-filled, or air-filled lesions in

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

are known as pneumocysts. When a pneumocyst is found in a bone it is called an intraosseous pneumocyst, or a vertebral pneumocyst when found in a

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

Cause

A pneumatocele results when a lung laceration, a cut or tear in the lung tissue, fills with air. A rupture of a small airway creates the air-filled cavity. Pulmonary lacerations that fill with blood are called

pulmonary hematoma A pulmonary hematoma is a collection of blood within the tissue of the lung. It may result when a pulmonary laceration fills with blood. A lung laceration filled with air is called a pneumatocele. In some cases, both pneumatoceles and hematom ...

s. In some cases, both pneumatoceles and

hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is ...

s exist in the same injured lung. A pneumatocele can become enlarged, for example when the patient is mechanically ventilated or has

acute respiratory distress syndrome Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin co ...

, in which case it may not go away for months. Intraosseous pneumatocysts in the bone are rare and of unclear origin. They are benign and usually without symptoms. They are also found around a sacroiliac joint, and there has been one reported case of an acetabular pneumocyst.

Diagnosis

Diagnosis can be made using

chest X-ray A chest radiograph, chest X-ray (CXR), or chest film is a Projectional radiography, projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common fi ...

; the lesion shows up as a small, round area filled with air.

Computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

can give a more detailed understanding of the lesion.

Differential diagnoses In healthcare, a differential diagnosis (DDx) is a method of analysis that distinguishes a particular disease or condition from others that present with similar clinical features. Differential diagnostic procedures are used by clinicians to dia ...

– other conditions that could cause similar symptoms as pneumatocele include

lung cancer Lung cancer, also known as lung carcinoma, is a malignant tumor that begins in the lung. Lung cancer is caused by genetic damage to the DNA of cells in the airways, often caused by cigarette smoking or inhaling damaging chemicals. Damaged ...

tuberculosis Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...

, and a

lung abscess Lung abscess is a type of liquefactive necrosis of the lung tissue and formation of cavities (more than 2 cm) containing necrotic debris or fluid caused by microbial infection. This pus-filled cavity is often caused by aspiration, which m ...

in the setting of hyper IgE syndrome (aka Job's syndrome), as a complication of COVID-19 pneumonitis, or on its own, often caused by ''

Staphylococcus aureus ''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posi ...

'' infection during

cystic fibrosis Cystic fibrosis (CF) is a genetic disorder inherited in an autosomal recessive manner that impairs the normal clearance of Sputum, mucus from the lungs, which facilitates the colonization and infection of the lungs by bacteria, notably ''Staphy ...

Management and treatment

Treatment typically is supportive and includes monitoring and observation.

Cause

Diagnosis

Management and treatment

References

Further reading