1. LUNG PATHOLOGY

2. Review Of Anatomy & physiology
• Cartilage is present to
level of proximal
bronchioles
• Beyond terminal
bronchiole gas exchange
occurs
• The distal airspaces are
kept open by elastic
tension in alveolar walls

3. Mechanics of Breathing
• Inspiration
– Active process caused mainly by contraction of
diaphragm . Accessory muscles may used during
exercise and distress
• Expiration
– Quiet breathing is a passive process but can
become active , with forced expiration
• Typical volume in normal breathing: 500
ml air

4. Pathology
Congenital Anomalies
Atelectasis
Acute Lung injury
Obstructive diseases
Restrictive diseases
Pulmonary vascular diseases
Pulmonary Infections
Tumors
Pleural diseases

5. Pulmonary Atelectasis

8. Acute lung injury
Pulmonary
Edema
Acute Respiratory
Distress
Syndrome
Acute Interstitial
Pneumonia

13. Obstructive Pulmonary
Diseases
Asthma
Emphysema
Chronic
bronchitis
Bronchiectasis

14. Asthma
•Asthma is a chronic inflammatory disorder of the airways that
causes recurrent episodes of wheezing, breathlessness, chest
tightness, and cough, particularly at night and/or in the early
morning.
•These symptoms are usually associated with widespread but
variable bronchoconstriction and airflow limitation that is at least
partly reversible, either spontaneously or with treatment.

15. Bronchial Asthma
Extrinsic
• type-I (IgE-mediated)
hyper-sensitivity or
allergic reaction
• Triggered by
environmental antigens
(dust, pollens, food, ..)
• family history of Atopy
• Childhood
Intrinsic
• Not allergic
• Triggered by respiratory
tract infections &drugs
(aspirin).
• No family history
• Adult

16. Pathology of asthma

17. These lungs appear essentially normal, but are normal-appearing because
they are the hyperinflated lungs of a patient who died with status
asthmaticus.

19. • Between the bronchial cartilage at the right and the bronchial lumen filled with
mucus at the left is a submucosa widened by smooth muscle hypertrophy and
inflammation (mainly eosinophils).
• These are changes of bronchial asthma. The peripheral eosinophil count or the
sputum eosinophils can be increased during an asthmatic attack.

20. • At high magnification, the numerous eosinophils are
prominent from their bright red cytoplasmic granules in this
case of bronchial asthma.

21. Bronchiectasis
• Is the permanent dilation of bronchi and
bronchioles caused by destruction of the
muscle and elastic supporting tissue

22. • This is another form of obstructive lung disease grossly in the mid lower portion of
the lung, the patient has recurrent infections because of the stasis in these airways.
• Copius purulent sputum production with cough is typical

23. •
•
A closer view demonstrates the focal area of dilated bronchi with bronchiectasis.
Bronchiectasis tends to be localized with disease processes such as neoplasms and aspirated
foreign bodies that block a portion of the airways.
Widespread bronchiectasis is typical for patients with cystic fibrosis who have recurrent
infections and obstruction of airways by mucus throughout the lungs

25. •
•
•
Bronchiectasis is seen here. The repeated episodes of inflammation can result in scarring,
which has resulted in fibrous adhesions between the lobes.
Fibrous pleural adhesions are common in persons who have had past episodes of
inflammation of the lung that involve the pleura.
With extensive involvement, the pleural space may be obliterated.

28. Chronic Bronchitis
•Chronic productive cough on most days of 3 consecutive
months in 2 consecutive years Providing other causes have
been excluded..
•The pathological hallmarks of chronic bronchitis are
congestion of the bronchial mucosa and a prominent increase
in the number and size of the bronchial mucus glands.

30. •
•
•
Chronic bronchitis does not have characteristic pathologic findings, but is defined
clinically as a persistent productive cough for at least three consecutive months in at
least two consecutive years.
Most patients are smokers.
Often, there are features of emphysema as well.

31. Emphysema
• Abnormal and permanent dilatation of air
spaces associated with destruction of their walls.

34. Types

35. Centriacinar Vs. Panacinar

38. • The chest cavity is opened at
autopsy to reveal numerous
large bullae apparent on the
surface of the lungs in a patient
dying with emphysema.
• Bullae are large dilated
airspaces that bulge out from
beneath the pleura.
• Emphysema is characterized by
a loss of lung parenchyma by
destruction of alveoli so that
there is permanent dilation of
airspaces.

39. • On cut section of the
lung, the dilated
airspaces with
emphysema are seen.
• Although there tends to
be some scarring with
time because of
superimposed infections,
the emphysematous
process is one of loss of
lung parenchyma, not
fibrosis.

40. Restrictive Pulmonary
Diseases
Fibrosing
Granulomatous
Eosinophilic
Smoking
Related

41. IPF
NSIP
Cryptogenic Organizing
pneumonia
Fibrosing
Diseases
CT Diseases
pneumoconiosis
Drug reactions
Radiation pneumonia

44. CWP
Pneumoconiosis
Silicosis
Asbestosis

50. Granulomatous
diseases
Sarcoidosis
Hypersensitivity
pneumonia

52. sarcoidosis

54. Pulmonary vascular
Diseases
Pulmonary
Embolism,
Hemorrhage and
Infarction
Pulmonary
Hypertension
Diffuse Pulmonary
Hemorrhage
Syndrome

57. Community Acquired Pneumonia
Community Acquired Atypical
pneumonia
Hospital Acquired Pneumonia
Pulmonary
Infections
Aspiration Pneumonia
Chronic Pneumonia
Necrotizing Pneumonia
Pneumonia of
Immunocompromised Host

58. Morphological Types
Lobar Pneumonia
Bronchopneumonia

64. • The cut surface of this
lung demonstrates the
typical appearance of a
bronchopneumonia with
areas of tan-yellow
consolidation.
• Remaining lung is dark
red because of marked
pulmonary congestion.
•
Bronchopneumonia is
characterized by patchy
areas of pulmonary
consolidation.

65. • Here is another
example of a
bronchopneumonia.
• The lighter areas
that appear to be
raised on cut surface
from the
surrounding lung are
the areas of
consolidation of the
lung.

66. • At higher magnification,
the pattern of patchy
distribution of a
bronchopneumonia is seen.

67. • This is a lobar
pneumonia in which
consolidation of the entire
left upper lobe has
occurred.
• This pattern is much less
common than the
bronchopneumonia
pattern.

68. • A closer view of the
lobar pneumonia
demonstrates the
distinct difference
between the upper
lobe and the
consolidated lower
lobe.

69. • The pleural surface at
the lower left
demonstrates areas of
yellow-tan purulent
exudate.
• Pneumonia may be
complicated by a
pleuritis.
• Initially, there may just
be an effusion into the
pleural space. There
may also be a fibrinous
pleuritis.
• However, bacterial
infections of lung can
spread to the pleura to
produce a purulent
pleuritis.
• A collection of pus in
the pleural space is
known as empyema.

70. Here is the gross
appearance of a lung
with tuberculosis.
Scattered tan granulomas
are present, mostly in
the upper lung fields.
Some of the larger
granulomas have
central caseation.
Granulomatous disease of
the lung grossly
appears as irregularly
sized rounded nodules
that are firm and tan.
Larger nodules may have
central necrosis known
as caseation

71. • This is another
example of
Granulomatous
disease of the lung.
• The pattern of
smaller nodules
which have a
propensity for
upper lobe
involvement
suggests a
granulomatous
process rather than
metastatic disease.

72. On closer inspection, the
granulomas have
areas of caseous
necrosis.
This is very extensive
granulomatous
disease.
This pattern of multiple
caseating granulomas
primarily in the upper
lobes is most
characteristic of
secondary
(reactivation)
tuberculosis.

73. • When there is
extensive caseation
and the granulomas
involve a larger
bronchus, it is
possible for much of
the soft, necrotic
center to drain out and
leave behind a cavity.
• Cavitation is typical
for large granulomas
with tuberculosis.

74. There is a small tan-yellow
subpleural granuloma in
the mid-lung field on the
right. In the hilum is a
small yellow tan
granuloma in a hilar
lymph node next to a
bronchus.
This is the "Ghon
complex" that is the
characteristic gross
appearance with primary
tuberculosis.

75. • The Ghon
complex is seen
here at closer
range.
• Primary
tuberculosis is the
pattern seen with
initial infection
with tuberculosis
in children.

76. Well-defined granulomas are seen here. They have rounded outlines. The one toward
the center of the photograph contains Langhans giant cells.
Granulomas are composed of transformed macrophages called epithelioid cells along
with lymphocytes, occasional PMN's, plasma cells, and fibroblasts. The localized,
small appearance of these granulomas suggests that the immune response is fairly
good.

77. At low magnification, this photomicrograph reveals multiple
granulomas.

78. • The edge of a granuloma is shown here at high magnification.
• At the upper right is amorphous pink caseous material composed of the necrotic
elements of the granuloma as well as the infectious organisms.
• This area is ringed by the inflammatory component with epithelioid cells,
lymphocytes, and fibroblasts

79. • At high magnification, the granuloma demonstrates that the epithelioid macrophages
are elongated with long, pale nuclei and pink cytoplasm.
• The macrophages organize into committees called giant cells. The typical giant cell
for infectious granulomas is called a Langhans giant cell and has the nuclei lined up
along one edge of the cell.

80. • In order to find the mycobacteria in a tissue section, a stain for acid fast bacilli
is done (AFB stain).

81. • Seen here are two lung
abscesses, one in the
upper lobe and one in the
lower lobe of this left
lung.
• An abscess is a
complication of severe
pneumonia, most
typically from virulent
organisms such as S.
aureus.

82. • At higher magnification can be seen a patchy area of alveoli that are filled with
inflammatory cells.
• The alveolar structure is still maintained, which is why a pneumonia often
resolves with minimal residual destruction or damage to the lung.

83. • At high magnification, the alveolar exudate of mainly neutrophils is seen. The
surrounding alveolar walls have capillaries that are dilated and filled with
RBC's. Such an exudative process is typical for bacterial infection.
• This exudate gives rise to the productive cough of purulent yellow sputum seen
with bacterial pneumonias.

84. • More virulent bacteria and/or more severe pneumonias can be associated with
destruction of lung tissue and hemorrhage.
• Here, alveolar walls are no longer visible because there is early abscess
formation. There is also hemorrhage.

85. • At higher magnification, early abscessing pneumonia is shown.
• Alveolar walls are not clearly seen, only sheets of neutrophils.

86. Lung Tumors

87. Squamous Cell CA
Small Cell CA
Adenocarcinoma
Lung
Tumors
Large Cell CA
Adenosquamous CA
Carcinoid Tumor
CA of Salivary gland type
Unclassified CA

88. • This is a squamous
cell carcinoma of
the lung that is
arising centrally in
the lung (as most
squamous cell
carcinomas do).
• It is obstructing the
right main
bronchus.
• The neoplasm is
very firm and has a
pale white to tan
cut surface

89. • This is a larger
squamous cell
carcinoma in which
a portion of the
tumor demonstrates
central cavitation,
probably because the
tumor outgrew its
blood supply.
• Squamous cell
carcinomas are one
of the more common
primary
malignancies of lung
and are most often
seen in smokers

90. • In this squamous cell carcinoma at the upper left is a squamous
eddy with a keratin pearl.
• At the right, the tumor is less differentiated and several dark
mitotic figures are seen.

91. • This is a peripheral
adenocarcinoma of
the lung.
• Adenocarcinomas and
large cell anaplastic
carcinomas tend to
occur more
peripherally in lung.
• Adenocarcinoma is the
one cell type of
primary lung tumor
that occurs more often
in non-smokers and in
smokers who have quit.

92. • This is
Bronchioloalveolar
carcinoma.
• Seen here is the
multifocal variant
that appears grossly
as a pneumonic
consolidation.
• Most of the upper
lobe toward the
right has a pale tan
to grey appearance

93. • Microscopically, the bronchioloalveolar carcinoma is composed of
columnar cells that proliferate along the framework of alveolar septae.
• The cells are well-differentiated. These neoplasms in general have a
better prognosis than most other primary lung cancers

94. • Arising centrally in
this lung and
spreading extensively
is a small cell
anaplastic (oat cell)
carcinoma.
• The cut surface of
this tumor has a soft,
lobulated, white to
tan appearance.
• Oat cell carcinomas
are very aggressive
and often
metastasize widely
before the primary
tumor mass in the
lung reaches a large
size

95. • Here is an oat cell
carcinoma which is
spreading along the
bronchi.
• The speckled black
rounded areas
represent hilar lymph
nodes with metastatic
carcinoma.
• The prognosis is poor.
• Oat cell carcinomas
occur almost
exclusively in
smokers.

96. • This is the microscopic pattern of a small cell anaplastic (oat cell)
carcinoma in which small dark blue cells with minimal cytoplasm
are packed together in sheets

97. • The dense white
encircling tumor mass
is arising from the
visceral pleura and is a
mesothelioma.
• These are big bulky
tumors that can fill the
chest cavity.
• The risk factor for
mesothelioma is
asbestos exposure.

98. • Here are larger but
still variably-sized
nodules of metastatic
carcinoma in lung

99. • These tan-white
nodules are
characteristic for
metastatic
carcinoma.
• Metastases to the
lungs are more
common even
than primary lung
neoplasms.

100. Thanks