1. The document discusses various cavitary and cystic lung lesions including causes such as infection, neoplasms, vascular diseases, and congenital abnormalities. 2. Common infectious etiologies of cavities include lung abscess caused by bacteria like Staph aureus, and tuberculosis which often involves the apical regions. 3. Neoplasms such as lung cancer or metastases can cause cavitation, while rheumatological diseases like Wegener's granulomatosis and infarction can result in multiple cavities. 4. Cystic lung lesions include pneumatoceles, bullae, blebs, bronchogenic cysts, and sequestrated lungs which have distinct features and causes discussed in the document.

1. Cavitary and Cystic lesions
高雄長庚醫院 胸腔內科
曾嘉成醫師

2. Cavity and Cyst
 Cavity: a gas containing space within the
lung surrounded by a wall whose thickness
is greater than 1 mm.
 Cyst: a gas containing space with a well-
defined thin wall (< 1 mm) not related to
emphysema.

3. Lucent lesion
 Bilateral
hyperlucency
 Unilateral
hyperlucency
 Solitary
hyperlucency
 Multiple
hyperlucency

4. Cavity: Causes (1)
 Inflammation:
– Pyogenic infection.
– TB.
– Fungus infection.
– Parasites.
 Neoplasm:
– Primary lung cancer.
– Metastases.
– Lymphoma

5. Cavity: Causes (2)
 Vascular:
– Rheumatoid.
– Wegener’s granulomatosis.
– Infarct (thromboemboli or septic emboli).
 Inhalation:
– Silicosis and coal worker’s pneumoconiosis.
 Congenital cyst:
– Pulmonary sequestration, bronchogenic cyst, and
congenital cystic adenomatoid malformation.

6. Infective, i.e. abscesses
staphylococcus aureus, klebsiella pneumoniae, tuberculosis,
aspiration, others
Neoplastic
carcinoma of the bronchus, metastases, Hodgkin’s disease
Vascular
Infarction
Abnormal lung
cystic bronchiectasis, infected emphysematous bulla,
sequestrated lung, bronchogenic cyst
Granulomas
Wegener’s granulomatosis, rheumatoid nodules,
progressive massive fibrosis
Traumatic
hematoma, traumatic lung cyst
Pseudocyst????
Lung Cavities

7. Differential Diagnosis (1)
 Cavitary wall:
– Thick: favor lung abscess, primary lung ca, metastasis,
Wegener’s granulomatosis.
– Thin: favor chronic infection (Coccidiodomycosis,
Paragonimiasis).
– Wall thickness: (measure thickest part)
 < 4 mm favor benign.
 4-15 mm inconclusive.
 > 15 mm favor malignancy.

8. Differential Diagnosis (2)
 Character of the Inner Lining(內緣):
– Nodular, irregular: malignancy.
– Shaggy(毛毛的): acute lung abscess.
– Smooth

9. Differential Diagnosis (3)
 Nature of the Cavitary Content:
– Fluid: in most cases, the contents are liquid.
– Fungus ball.
– Pulmonary gangrene: irregular pieces of
sloughed necrotic lung parenchyma float like
icebergs in the cavity fluid.
– Water-lily sign: ruptured Echinococcus cyst
which float on the top of the fluid.

10. Differential Diagnosis (4)
 Associated Lesions:
– Surrounding air space consolidation: acute
edema, hemorrhage, exudate.
– Irregular reticular strands: chronic fibrotic scar.
 Location
– Upper lobe or lower lobe?
– S3 Vs S2

11. Differential Diagnosis (5)
 Multiplicity of Lesions:
– Solitary: typical for lung cancer, acute lung
abscess, post-traumatic lung cyst.
– Multiple: typical for metastases, Wegener’s
granulomatosis, Septic emboli.

12. Pentax Optio S

13. Cavity: Abscess (1)
 Associated Lesions:
– Surrounding air space consolidation: acute edema,
hemorrhage, exudate.
– Irregular reticular strands: chronic fibrotic scar
 Virulent pathogen  vasculitis  thrombosis
 necrosis  cavity
 Necrotizing pneumonia  Abscess

14. Cavity: Abscess (2)
 Pulmonary infection with cavitary
lesions
narrows the differential diagnosis
– Viral and mycoplasma pneumonia ---
unlikely
– Pneumococcal pneumonia --- rarely
– Most common pathogen
GPC: Staph, -hemolytic Strep,
GNB: Kleb, Pseudo, E. coli,
Anaerobes

15. Lung abscess, Klebsiella pneumoniae

16. Cavity: Abscess (3)
 Aspiration pneumonia frequently cavitate
– May subclinical aspiration
– Mixed GNB and anaerobes
– Cavity formation in a dependent portion
– Unconscious, poor oral hygiene, alcoholism,
or tumor in mouth, nasopharynx or larynx

17. Cavity: Abscess (4)
 Pulmonary gangrene:
– Relative uncommon complication
– Very acute ischemic necrosis.A nonviable lung
detached from a viable lung  cavity
– “Ball in hole” --- like fungus ball
– Most common: Klebsiella pneumoniae.
– Pneumococcus, H. influ, S. aureus, Anaerobes,
Mucormycosis, and Aspergillus.
– Early diagnosis  surgical intervention

20. Pulmonary gangrene
– Relative uncommon
– Very acute ischemic necrosis
– “Ball in hole” -- like fungus ball
– Most common: Kleb. pneum.
– Pneumo, H. influ, S. aureus,
Anaerobes, Muco. Aspergillus
– Early diagnosis
 surgical intervention

21. Lung abscess vs Empyema
 Lung abscess : spherical, thick wall, the
air-fluid levels are equal in length
regardless of the radiographic projection.
 Empyema : pleural disease, lens-shaped,
longer in one view than in the other
 Lung abscess  bronchopleural fistula 
hydropneumothorax ( empyema )

22. Lung abscess Hydropneumothorax

23. Lung abscess >>>------------------------>>> empyema

24. Cavity: Tuberculosis (1)
 好發位置
– Apicoposterior of upper & superior of lower lobe
 TB in cavitary phase indicates
-- active and at risk of dissemination
– Hematogenous spreading:
diffuse fine nodules, sharply defined
– Bronchogenic spreading:
larger (2-5mm) and ill-defined borders

25. Cavity: Tuberculosis (2)
 Features unlike TB
– Solitary cavity at ant segment of upper lobe
– Isolated cavities at lower lobe
 Features suggesting of TB
– Associated reticular pulmonary scars
– Volume loss in the involved lobe
– Pleural thickening and calcification.
– Calcified hilar or mediastinal lymph nodes

26. Tuberculosis

27. 1.Tuberculosis
2.DM

28. Cavity: Mycetoma
 Fungus ball in an “existed” hole
– “Hole”: active or inactive TB (most common),
lung abscess, pulmonary sequestration,
cancer, sarcoidosis, etc.
 Generally asymptomatic and indolent
 Hemoptysis: life-threatening complication
 Air crescent
 Aspergillus fumigatus

30. Aspergilloma

31. Aspergilloma in old TB cavity

33. Aspergilloma in old
coccidiodomycosis cavity

34. Fungus
 Cavity formation:
– Cryptococcus
– Aspergillus
– Mucormycosis
– Coccidiodomycosis
 Nocardia

35. Coccidioidomycosis

36. Coccidioidomycosis

37. Hydatid Cyst
 Echinococcus, a parasite
 3 layers of hydatid cyst
– Outer: tough pericyst, produced by host
– Middle: laminated layer, produced by parasite
– Inner: unicellular, germinal layer, produce fluid and cyst
 Spherical, well-defined, homogenous cyst
growing and asymptomatic until rupture
 Water-lily sign: air entering outer and middle layer
 cyst fragment floating in the cavity

41. Cavity: Neoplasm (1)
 Primary lung cancer:
– epidermoid ca.; bronchioloalveolar cell ca.
 Metastatic cancer: (NPC,Eso. Ca,Cx Ca)
– Man: head and neck in origin.
– Woman: Gyn. tract in origin.
 Radiological findings of cavity is not a
reliable signs to D.D. benign or malignancy

42. Cavity: Neoplasm (2)
 Features suggesting malignancy
– Not significant amount of fluid
– Eccentric cavitation
– Thick wall
– Lobulated and nodular wall

43. Lung cancer
Sq Carcinoma

44. Lung cancer
Sq Carcinoma

45. Lung cancer
Sq Carcinoma

46. Lung cancer
Sq Carcinoma

47. Sq Carcinoma
Stalagmites/stalactites

48. Lung cancer,
Sq cell carcinoma

49. Lung cancer,
sq cell carcinoma

50. Squamous cell ca. of Esophagus

51. Cervix Ca with meta

52. Rheumatoid Arthritis
 Pleural effusion
 Nodules
– Necrobiotic nodules
– Cavitate
 Interstitial fibrosis
 Erosion of posterior ribs
 Kaplan syndrome
– Coal worker pneumoconiosis
 Bronchiolitis obliterans

53. Rheumatoid nodule with central cavity

55. Inhalation Diseases
 Pneumoconiosis:
– ischemic necrosis of the conglomerated
mass
 Silicosis:
– May cavitation by itself
– Most likely due to TB superinfection
--- TB must be ruled out in all patients
with silicosis + cavitation

56. SONY DSC V1

57. Cystic lesion
 Pneumatocele
 Bullae
 Bleb
 Bronchogenic cyst
 Pulmonary sequestration

58. Pneumatocele
 A thin wall space, caused by
– Infection: S. aureus in infants & children
Pneumocystis carini in AIDS p’ts
– Hydrocarbon aspiration
– Also occurs following trauma
 Invariably transient
 Mechanism:
– check valve obstruction of the airways
– Subpleural collection of air, dissection occurs through
the interstitium of the lung

59. Staph. pneumonia with pneumatocele

61. Bulla (1)
 A sharp demarcated, air containing space 1
cm or more in diameter that possess a
smooth wall 1 mm or less in thickness.
 Usually occurs with other lung disease
(emphysema or infection).
 由infection 引起者，常伴有adjacent
parenchymal scarring。

62. Bulla (2)
 Secondary Sign: compression or
displacement of adjacent structures (lung
and mediastinum).
 Bullae are characteristically poorly
ventilated and unperfused.

63. Bullae

64. 1.COPD bullae
2.Fusion rib
3.Calcified TB

65. Infected bullae

66. Infected bullae

67. Tension Bulla

68. Bleb
 Localized collection of air located within the
pleura.
 Most common occurs over lung apex,
seldom exceeds 1 cm.
 Mechanism: alveolus rupture >> air
dissection through interstitial tissue into
the thin fibrous layer of visceral pleura.

71. Bronchogenic Cysts (1)
 Mechanism
– Localized portions of the tracheobronchial tree
separated from normal airway during branching
process and do not further develop
 Usually solitary, thin-walled, and spherical
 Filled with mucoid or serous fluid and do not
communicate with the airways unless infected.
 Pathology: the wall typically contains cartilage
and smooth m. (important for diagnosis)

72. Bronchogenic Cysts (2)
 Mediastinal bronchogenic cyst (65-90%)
– paratracheal, carinal, hilar, paraesophageal …
– The first 2 are more common, more on R’t side
– Rarely communicates with airways
 Pulmonary bronchogenic cyst
– Sharply circumscribed round nodule
– In the medial third of the lungs, esp. lower lobes
– Not communicate with the airways until infected

73. Bronchogenic cyst

74. Bronchogenic cyst

75. Pulmonary Sequestration
 Intralobar and Extralobar sequestration
DD by enclosing pleura and L-L or L-R shunt
 Intralobar sequestration
– 好犯 post. basal segment of lower lobe, left side
and contiguous with the diaphragm
– recurrent pneumonia
– Less common: cystic mass (with or without fluid
levels) with prominent vessel --- due to infection

76. Pulmonary sequestration

77. Pulmonary sequestration

78. Casio EX Z3

79. Multiple Lucent Lesions-(I)
I. Cavity
A. Infection (bacterial, fungal, mycobacterial and
parasite)
B. Neoplasm
1. Metastasis
2. Bronchioloalveolar cell carcinoma
C. Vascular
1. Wegener’s granulomatosis
2. Rheumatoid disease
3. Infarct (thromboemboli or septic emboli)

80. Multiple Lucent Lesions-
(II)
II. Cystic bronchiectasis
III. Pneumatocele
IV. Bullae
V. Congenital cystic adenomatoid
malformation (CCAM)

81. Lung abscess
Multiple aspiration

82. Multiple bullae

83. Necrotizing pneumonia,
Klebsiella pneumoniae

84. Tuberculosis

85. Lung cancer,
adenocarcinoma

86. Adenocarcinoma

87. Septic emboli, cavity
Staphylococcus
aureus

88. Vascular Lesions
 Wegener’s granulomatosis and
rheumatoid arthritis:
– The 2 most likely collagen vascular
disease to cause cavitation.
 Pulmonary infarction:
– Occur in area of infarction greater than
4cm in diameter and happen 2 weeks
after appearance of the consolidation.

89. Wegener’s granulomatosis (1)
 Adults in their thirties to fifties
 Typical pattern:
--- multiple nodules ranging from 1-10 cm
 Nodules tend to increase in size and number
 Cavitation:
– 50%
– Thick wall, irregular and shaggy inner lining
– Less commonly -- thin wall or air-fluid level

90. Wegener’s granulomatosis (2)
 2nd common CXR pattern
– Multiple non-circumscribed lesions
– Acute air space consolidation or ground-glass
opacities secondary to pulmonary hemorrhage
--- localized, or bilateral; patchy, or confluent.
– With or without the presence of nodules
 Other findings
– Airway involvement is also common
– Pleural effusion: 10%; unilateral or bilateral

91. Wegener’s
granulomatosis,
Fraser et al,
Synopsis of diseases
of the chest, 2nd ed.

92. Wegener’s granulomatosis

93. Sebastian Lange, Radiology of chest diseases, 1990

94. Congenital cystic adenomatoid malformation,
(CCAM)

95. Cystic Bronchiectasis
 One of the 4 types( cylindrincal, varicose,
saccular, cystic) of bronchiectasis
 Not true cavity, but ballooned dilatation of
multiple terminal bronchi
 Causes:
– Congenital
– Recurrent infection – bacteria, TB,
cystic fibrosis, agammaglobulinemia,
– ABPA

96. Cystic bronchiectasis

97. Cystic Bronchiectasis

98. Histiocytosis X (Langerhan’s cell
histiocytosis)
 Young adult; male=female
 Dry cough, SOB, pneumothorax, or asymptomatic
 Histiocytes & eosinophils aggregate, no granuloma
 Upper lobe predominence, sparing lung base
 CXR and CT
nodules  cavitated nodules or cysts  honeycomb
 Spontaneous pneumothorax
 Concomitant nodules and cysts in upper and middle
lung fields sparing lung base is diagnostic

99. Histiocytosis X

100. Lymphangioleiomyomatosis
 Premenopausal women predominence
 Proliferation of smooth muscle-like LAM cells in
small airway, microvasculature and lymphatics
 Airway obs, cystic change of lung, pulmonary
hemorrhage, pneumothorax, chylothorax
 Early stage
– CXR: diffuse reticulonodular pattern
– HRCT: air-cysts diffusely distributed in all lung zones
no nodules, no lobe predominence
 End stage: honeycombing

101. Lymphangioleiomyomatosis

102. LAM

103. LAM

104. Canon EOS 10D

105. Colon
Diaphragm rupture
Diaphragm eventration

106. Colon herniation

107. Colon herniation

109. Plumbage