For quick review for D/D of lung cavities you can go through it. always waiting for your suggestions so that i can improve it...

1. Dr. Bijay Kr. Yadav
Radiology Resident
A.K. Akhunbaev KSMA

2.  A lung cavity or pulmonary cavity is an abnormal, thick-
walled, air-filled space within the lung.
 The terms cavity and cyst are frequently used
interchangeably; however, a cavity is thick walled (at
least 5 mm), while a cyst is thin walled (4 mm or less).
The distinction is important because cystic lesions are
unlikely to be cancer, while cavitary lesions are often
caused by cancer.
 Diagnosis of a lung cavity is made with a chest X-
ray or CT scan of the chest, which helps to exclude
mimics like lung cysts, emphysema, bullae, and cystic
bronchiectasis.

3. Causes:
1. Cancer:
2. Autoimmune:
3. Vascular:
4. Infection:
5. Trauma:
6. Youth:

4.  The most common cause of a single lung cavity is lung cancer.
 Usually, the cavity forms because the cancer grows more
rapidly then its blood supply, resulting in necrosis in the
central part of the cancer.
 Primary bronchogenic carcinoma, especially Squamous cell
carcinoma (scc) of the lung is more likely to develop
cavitations than lung adenocarcinoma or large cell lung
carcinoma.
 Other primary cancers of the lung, such as lymphoma
and Kaposi’s sarcoma can also cavitate, especially in
immunocompromised people.

5.  Of all bronchial carcinomas, 10–15 % are cavitary.
 Cavitation is secondary to tumoural necrosis.
Radiographic features:
 Neoplasms are typically of variable size, round with
irregular thick walls of solitary mass (greater than 4
mm) on CT scan, with higher specificity for neoplasm in
those with a wall thickness greater than 15 mm.
 Center mass outside line is spiked due to lymphangitis
& Inner wall line is smooth.

6. I. Granulomatosis with polyangiitis (GPA):
 Previously known as Wegener granulomatosis, is a
multisystem necrotising non-caseating granulomatous
c-ANCA positive vasculitis affecting small to medium sized
arteries, capillaries, and veins.
Plain radiograph:
 Chest radiographs may show multiple nodules or masses that
can be extremely variable in size (from a few millimetres to
many centimetres)
 Although cavitation is present in ~ 50% of cases, is seen less
frequently on plain film
 Airspace opacities may represent consolidation or pulmonary
haemorrhage

7. II. Rheumatoid pulmonary nodule:
 Rheumatoid pulmonary nodules are a rare pulmonary
manifestation of rheumatoid arthritis. They are thought to occur in
<1% of patients with rheumatoid arthritis.
Radiographic features:
i. Plain Radiograph:
 Not very sensitive (may only be detected a very small proportion of
cases on plain film).
ii. CT- On HRCT or CT of the chest:
 Nodules can be quite variable in appearance: associated cavitation
may be seen
 May be single or multiple
 Size ranges from 0.5-7 cm
 Rarely these nodules can have associated calcification
 Tend to be peripheral, subpleural or pleural

8. Pulmonary infarction:
 Pulmonary embolism (a blood clot in the lung)
causes pulmonary infarction (the death of lung tissue) and
only about 5% of pulmonary infarctions result in lung cavities
 occurs in the minority (10-15%) of patients with Pulmonary
embolism.
Radiographic features:
 wedge-shaped (less often rounded) juxtapleural
opacification (Hampton hump) without air
bronchograms
 more often in the lower lobes

9.  Several groups of microorganisms may cause cavitary
lesions in the lungs:
◦ Common bacteria are Streptococcus p., Staph. aureus,
Klebsiella p., H. influenzae.
◦ Typical and atypical mycobacterium.
◦ Fungi: Aspergillosis.

10.  Pulmonary abscess occurs as a complication of
pneumonia.
 The most common appearance of a lung abscess is an
asymmetric cavity with an air-fluid level and a wall with
a ragged or smooth border.
 They may occur anywhere in the lungs. Usually,
intermediate to thick wall thickness with a peripheral
contrast enhancement and necrotizing centre is visible.
 If the abscess is located peripherally, there may be local
pleural thickening or an empyema.

12.  The cavities in tuberculosis, which occur in 50 percent of
patients, are usually located in upper zones of the lobes.
 They are often surrounded by satellite nodules.
 The cavity wall thickness may vary considerably, and
the cavity wall may show rim enhancement on CT.
 If there is affection of the lymph nodes, one may see
nodal rim enhancement around central necrosis.

15.  The radiological division of primary and secondary
features has been debunked.
 However, a radiological pattern does exist; upper lobe
cavitary disease is commonly seen in immunocompetent
adults, while lower lung zone disease, and pleural
effusions are commonly found in immunocompromised
patients.
 Miliary tuberculosis is hematogenous spread of disease,
which presents as small, 2–3 mm sized nodules. They
are usually located in the lower zones of the lobes and
may cavitate.

17.  Aspergillosis is caused by a fungus: Aspergillus fumigatus.
Radiographic features:
 On imaging, one may find a solitary cavitating or multiple
cavitating opacities or masses with a crescent-shaped air
collection in the nondependent part of the cavity
 On CT, initially there is consolidation, which may have a halo
of ground glass surrounding it. The nodules may cavitate.
 The wall of the preexisting cavity may be affected by the
aspergilloma and become irregular, but wall thickness
usually remains below 3 mm.

18. Pneumatocele:
 Are intrapulmonary gas-filled cystic spaces that can have a
variety of sizes and appearances.
 They may contain gas-fluid levels.
 If they are imaged during formation, they may have
surrounding consolidation and be difficult to distinguish
from abscesses.
Features that favour a pneumatocele over an abscess are:
◦ Smooth inner margins
◦ Little if any fluid content
◦ The wall, if visible, is thin and regular
◦ Tend to persist despite an absence of symptoms

19. Bronchogenic cysts:
 Bronchogenic cysts are congenital malformations of the
bronchial tree.
 They can present as a mediastinal mass that may enlarge and
cause local compression.
 It is also considered the commonest of foregut duplication
cysts.
Plain radiograph:
 The cysts usually appear as soft-tissue density rounded
structures. sometimes with compression of surrounding
structures.
 Occasionally such compression can lead to air-trapping and
a hyperlucent hemithorax.