26. Heterogeneous lung density having a zonal or geographic
pattern of distribution with
areas of “ground glass attenuation”
alternating with
areas of “decreased” lung density
27.
28.
29. MOSIAC PATTERN
DEPENDENT LUNG ONLY NONDEPENDENT LUNG
EXPIRATION
PRONE
POSITION
NO AIR
TRAPPING
NOT AIR TRAPPING
RESOLVE
RESOLVE
VESSEL SIZE
PLATE GROUND
ATELECTASIS GLASS
AIRWAYS
DECREASED NORMAL DISEASE
GROUND
VASCULAR GLASS
29
30. It refers to mixed densities
# Consolidation
# Ground Glass Opacities
# Normal Lung
# Mosaic Perfusion
• Signifies mixed infiltrative
and obstructive disease
31. Common cause are :
1. Hypersensitive pneumonitis
2. Sarcoidosis
3. DIP
31
32. LINEAR AND
RETICULAR
OPACITIES
NODULES AND
INCREASED LUNG NODULAR
ATTENUATION OPACITIES
PARENCHYMAL Consolidation
OPACIFICATION
Ground glass
HRCT PATTERN
CYSTIC LESIONS,
EMPHYSEMA, AND
BRONCHIEACTASIS
MOSAIC
ATTENUATION AND
PERFUSION
DECREASED LUNG
ATTENUATION
AIR TRAPPING ON
EXPIRATORY SCANS
33. LINEAR AND
RETICULAR
OPACITIES
NODULES AND
INCREASED LUNG NODULAR
ATTENUATION OPACITIES
PARENCHYMAL Consolidation
OPACIFICATION
Ground glass
HRCT PATTERN CYSTIC
LESIONS, EMPHYSE
MA, AND
BRONCHIEACTASIS
MOSAIC
ATTENUATION AND
PERFUSION
DECREASED LUNG
ATTENUATION
AIR TRAPPING ON
EXPIRATORY SCANS
36. Nonspecific term Destruction of airspaces
Well defined >1cm Low attenuation areas
Smooth walled <3mm Wall-less <1mm
Epithelial or fibrous wall
Area of emphysema
Necrosis or defoliation >1cm
Epithelial or fibrous wall
Irregular Wall >3mm
Cyst/ Bulla + acute
pnemonia
Small bulla touching the
pleura
37.
38.
39. Lung cysts well defined , circumscribed air
containing lesions with a wall thickness of less than
4mm. They are lined by usually fibrous or cellular
epithelium.
Cavities are defined as radiolucent areas with a wall
thickness of more than 4mm and are seen in
infection (TB, Staph, fungal, hydatid), septic emboli,
squamous cell carcinoma and Wegener's disease.
40. Hyperlucent ring formed through necrosis or
defoliation is called a cavity.
Ring expanded through pressure or fusion of
alveolar spaces is called cyst
When the wall is distinct call it a cyst
When its not distinct call it emphysematous cyst or
bullae.
42. Multiple bizarre shaped cysts. There was an upper lobe predominance. The
patient had a long history of smoking.
43. Multiple bizarre shaped cysts. There was an upper lobe predominance. The
patient had a long history of smoking.
44.
45. Aka., Pulmonary Histiocytosis X / Eosinophilic
Granuloma.
Probably an allergic reaction to cigarette smoke
since >90% are active smokers.
Upper and mid lobe predominance.
Early stages : Granulomatous nodules containing
Langerhans histiocytes and eosinophils.
Later stages : Granulomas are replaced by fibrosis
and the formation of cysts.
46. Early nodular stage:
Centrilobular granulomatous reaction by Langerhans
histiocytes.
Proliferation of Langerhan’s cells around the small
airways; cellular nodules develop and become
increasingly fibrotic as the disease progresses.
Cystic stage:
Bronchiolar obliteration causes alveolar wall fibrosis and
cyst formation often at different times.
48. The late phase is
characterised by
multiple cysts, the
largest of which has a
bizarre shape
characteristic of late
stage disease.
49. Depend on the stage of the disease.
In early disease,
Small irregular or stellate nodules in centrilobular
location.
As some nodules begin to cavitate there is
temporal heterogeneity.
50. Late stage (more commonly seen)
The cysts tend to be small (typically <1cm) and may
initially be round and thick-walled.
They may coalesce , become larger and have bizarre
shapes (bilobed or clover-leaf shaped)
Up to 20% present with pneumothorax
52. It started as small noduli, which progressed over time to cavitating nodules.
In the end this will progress to bizarre shaped cysts, that replace normal lung
tissue.
53. Early stage Langerhans cell histiocytosis with small nodules.
There are no cysts visible
56. The bizarre outline of and distribution (mid and
upper zonal with relative sparing of the lung
bases and the tip of the middle lobe/lingula) of
cysts is a useful diagnostic feature
57. Nodular LCH:
Sarcoidosis: perilymphatic distribution.
Metastases: random distribution.
Cystic LCH:
LAM: round cysts, evenly distribution in women in the
child-bearing age
Cystic bronchiectasis: 'signet ring sign'.
Centrilobular emphysema: no walls, central dot.
LIP
58.
59. The most challenging differential diagnosis in this
patient is centrilobular emphysema.
The upper lobe predominance is not helpful in the
differential as we can appreciate this in many
inhalational diseases.
Emphysema however is defined as airspaces
without definable walls.
Usually we can identify the central dot sign.
60. Emphysema:
when it is severe, can mimic Langerhans cell histiocytosis.
When it extends beyond the centrilobular area to the
edge of the secondary lobule, it may look as if it is cystic
with walls.
In patients with LCH, the pathologist may find LCH, but
also areas of emphysema, respiratory bronchiolitis and
even fibrosis.
So these smoking-related diseases do not represent
discrete entities.
61. 40 year old female with no history of smoking . Multiple cysts that are evenly
distributed througout the lung ( in contrast to LCH).Notice the pneumothorax.
62.
63. Lymphangioleiomyomatosis (LAM) is a
rare, idiopathic disorder occurring exclusively in
females of child-bearing age.
Clinical findings:
Majority of patients present with dyspnea.
Chylous pleural effusions (40%), Pneumothorax
(40%), hemoptysis (40%).
Patients die within 10 years of the onset of symptoms.
Pregnancy may exacerbate disease.
64. Characterized by progressive proliferation of spindle
cells, resembling smooth muscle.
Proliferation of these cells along the bronchioles
leads to air trapping and the development of thin-
walled lung cysts.
Rupture of these cysts can result in pneumothorax.
65. The cardinal histopathologic finding is the abnormal
proliferation of ‘immature’ smooth muscle cells
around the small airways, pulmonary vessels,
lymphatics and alveolar septa.
Interestingly, the pulmonary abnormalities of LAM
are similar to those seen in patients with tuberous
sclerosis.
66. LMG characterised by
areas of smooth muscle
proliferation (LAM cells)
which contribute to the
wall of a typical cyst.
67. Multiple thin-walled cysts of roughly uniform size.
Unlike LCH, the cysts in LAM tend to be rounded
and uniformly distributed throughout the
parenchyma with no regional sparing.
There is a conspicuous absence of nodules.
68. Numerous thin-walled cysts, surrounded by normal
parenchyma.
Round in shape and more or less uniform.
Cysts range from 2mm to 5cm in diameter,
Wall thickness ranges from barely perceptible to 4 mm.
Cysts are distributed diffusely throughout the lungs and
upper and lower lobes are involved to a similar degree.
Mediastinal or hilar adenopathy .
Chylous Pleural effusions (40%).
Recurrent pneumothorax (40%)
69.
70.
71. Langerhans cell histiocytosis:
> 90% are smokers, cysts have irregular shapes and the
basal costophrenic angles are spared.
Centrilobular emphysema:
characterized by airspaces that have no perceptible wall,
centrilobular artery seen as dot in the centre.
Lymphoid interstitial pneumonitis:
seen in patients with HIV and Sjogren syndrome.
72. LIP is uncommon, being seen mainly in patients
with autoimmune disease, particularly Sjogren's
syndrome, and in patients with AIDS.
Symptoms are nonspecific and often those of the
patient's underlying disease
HRCT findings are usually nonspecific.
73. LIP is a clinicopathological term for a pulmonary
lymphoproliferative abnormality associated with
several disease entities including connective tissue
disorders HIV infection and Dysproteinaemic states,
Idiopathic LIP is exceedingly rare.
On histologic examination there is a interstitial
cellular infiltrate comprising small, mature
lymphocytes and plasma cells.
74. there is a diffuse interstitial
infiltrate of lymphocytes,
most marked around the
bronchovascular bundles
and thickening of alveolar
walls.
75. Admittedly, HRCT may be wholly non-specific:
Variable combinations of
ground-glass opacification,
nodules (ill-defined centrilobular or subpleural) and
thickening of the interlobular septa,.
However, in some patients with LIP, the above
features may be associated with thin-walled cysts.
77. Lymphocytic interstitial pneumonia in Sjögren’s syndrome.
In addition to the diffuse ground-glass opacification there are multiple thin-walled cysts
in both lungs. At least two irregular nodules (arrows), representing amyloid deposition,
are noted in the right lower lobe
81. Permanent dilatation of the air spaces distal to
terminal bronchiole, accompanied by destruction of
their alveolar walls without obvious fibrosis
Emphysema typically presents as areas of low
attenuation without visible walls as a result of
parenchymal destruction.
82.
83. Most common type
Strongly associated with
smoking.
Often the centrilobular artery
is visible in the centre of these
lucencies (central DOT)
Most commonly in the upper
lobes
83
84. Histologic specimen shows areas of lung destruction surrounding a small
centrilobular artery (arrow)
85. Centrilobular emphysema due to smoking.
The periphery of the lung is spared (blue arrows).
Centrilobular artery (yellow arrows) is seen in the center of
the hypodense area
87. Affects the peripheral parts
of the secondary pulmonary
lobule adjacent to the pleura
and interlobar fissures
Produces subpleural
lucencies.
Can be isolated phenomenon
in young adults, or in older
patients with centrilobular
emphysema
87
88. Paraseptal emphysema is localized near fissures and
pleura and is frequently associated with bullae
formation (area of emphysema larger than 1 cm in
diameter).
Apical bullae may lead to spontaneous pneumothorax
92. Paraseptal emphysema Honeycomb cysts
Occur in a single layer at the pleural May occur in several layers in the
surface subpleural lung
Predominate in the upper lobes Predominate at the lung bases
Unassociated with significant fibrosis Asso with other findings of fibrosis.
Associated with other findings of -
emphysema
92
93. Complete destruction of the
entire secondary pulmonary
lobule.
An overall decrease in lung
attenuation
Reduction in size of pulmonary
vessels
Lower lobe predominance
In alpha-1-antitrypsin deficiency,
but also seen in smokers with
advanced emphysema
93
97. • Does not represent a specific histological
abnormality
• Emphysema characterized by large bullae
• Often associated with centrilobular and paraseptal
emphysema
98. Previously known as irregular or cicatricial emphysema
can be seen in association with fibrosis
with silicosis and progressive massive fibrosis or
sarcoidosis
98
99. Centrilobular Panlobular Paraseptal
emphysema emphysema emphysema
• Most common type • Affects the whole • Adjacent to the
• Irreversible secondary lobule pleura and
destruction of • Lower lobe interlobar fissures
alveolar walls in the predominance • Can be isolated
centrilobular • In alpha-1- phenomenon in
portion of the antitrypsin young adults, or in
lobule deficiency, but also older patients with
• Upper lobe seen in smokers centrilobular
predominance and with advanced emphysema
uneven distribution emphysema • In young adults
• Strongly associated often associated
with smoking. with spontaneous
pneumothorax
100. Centrilobular E Panlobular E Paraseptal E Paracicatricial E
Synonyms: Centriacinar emphysema. Panacinar emphysema. Distal acinar emphysema. Irregular emphysema.
Dilatation of the Dilatation of the entire Dilatation of the alveolar No consistent
respiratory bronchioles acinus from respiratory ducts & alveolar sacs. relationship to any
(in the central portion of bronchioles to alveolar portion of 2ry lobule.
the acini). sacs.
Pathology: Normal & Uniform enlargement of Focal areas of Emphysematous changes
emphysematous alveolar all acini through both emphysematous changes adjacent to areas of
spaces adjacent to each lungs. adjacent to normal lung. pulmonary scarring.
other
Site: Lung apex. Involves whole lung but Subpleural lung. Adjacent to areas of
Central areas with more sever at the lung pulmonary scarring.
sparing of the peripheral base.
areas.
Aetiology: Smoking. α1 anti-trypsin deficiency Smoking Pulmonary scarring
Chest x- Signs of hyperinflation.
ray: Signs of pulmonary hypertension.
Emphysematous bullae.
High Emphysematous spaces: Diffuse decrease in lung Peripheral (subpleural Areas of decreased
resolution Focal areas of decreased attenuation. and peribronchovascular) attenuation adjacent to
CT: attenuation, Pulmonary vascular areas of decreased pulmonary fibrosis.
More than 1 cm, pruning. attenuation less than Associated with traction
Without definable wall. Difficult to detect early, 1cm. bronchiectasis.
Surrounded by a normal because of lack of (if more than 1 cm it is
lung, adjacent normal lung. considered subpleural
Contains a central dot bullae).
representing pulmonary
arteriole.
101. A sharply demarcated area of emphysema ≥ 1 cm
A thin epithelialized wall ≤ 1 mm.
Usually associated with evidence of extensive
centrilobular or paraseptal emphysema
Uncommon as isolated finding, except in the apices
When emphysema is associated with predominant
bullae, it may be termed bullous emphysema
101
102. A thin-walled, gas-filled space within the lung,
Associated with acute pneumonia or hydrocarbon
aspiration.
• Often transient.
• Believed to arise from lung necrosis and
bronchiolar obstruction.
• Mimics a lung cyst or bulla on HRCT and cannot be
distinguished on the basis of HRCT findings.
102
103.
104. Thicker and more irregular walls than lung cysts
• In diffuse lung diseases - LCH, TB, fungal infections,
.
and sarcoidosis.
Also seen in rheumatoid lung disease, septic
embolism, pneumonia, metastatic tumor,
tracheobronchial papillomatosis, and Wegener
granulomatosis
104
108. Is the abnormal dilatation of the medium-sized bronchi
(>2 mm in diameter) caused by destruction of the
muscular and elastic components of bronchial walls.
The proximal bronchi are less affected because they have
more cartilage and are more resistant to dilation.
108
109. Bronchial dilatation
# The broncho-arterial ratio (internal diameter of the
bronchus /pulmonary artery) exceeds 1.
# In cross section it appears as “signet ring appearance”
Lack of bronchial tapering
# the earliest sign of cylindrical bronchiectasis
# One indication is lack of change in the size of an airway
over 2 cm after branching.
Visualization of peripheral airways
# Visualization of an airway within 1 cm of the costal
pleura is abnormal and indicates potential bronchiectasis
109
110. A signet-ring sign represents an axial cut of a dilated bronchus (ring) with
its accompanying small artery (signet).
114. # Bronchial wall thickening :
Normally wall of bronchus should be less than half the
width of the accompanying pulmonary artery branch.
# Mucoid impaction
# Air trapping and mosaic perfusion
114
115. Bronchiectasis (curved arrows) with mild to moderate bronchial wall thickening.
In addition, CT scan shows mucous plugging (straight arrows) and mosaic perfusion (∗)
118. # mildest form of this
disease,
# thick-walled bronchi
that extend into the
lung periphery and
fail to show normal
tapering
118
119. # beaded appearance of
bronchial walls - dilated
bronchi with areas of
relative narrowing
# string of pearls.
# Traction bronchiectasis
often appears varicose.
120.
121. # Group or cluster of air-
filled cysts,
# cysts can also be fluid
filled, giving the
appearance of a cluster
of grapes.
122. # Dilatation of intralobular
bronchioles because of
surrounding fibrosis
# Due to fibrotic lung
diseases
122
