Pathology - Pulmonary Images
Pathology Review
Pulmonary
Image
Slide #
Feature
1
Normal lung: A lung is bisected,
revealing branching conducting
airways (bronchi) and spongy
brown parenchyma.
2&3
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Normal bronchus: The bronchial
wall includes the respiratory
mucosa, smooth muscle,
submucosa with seromucinous
glands, and cartilage. The
epithelium is pseudostratified and
columnar, and consists of ciliated
cells, goblet cells and reserve
cells. Neuroendocrine
(Kulchitsky) cells cannot be
distinguished.
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Pathology - Pulmonary Images
4
Normal alveolar parenchyma:
Terminal and respiratory
bronchioles (*), alveolar ducts,
alveolar sacs, and a small artery
are shown.
5
Normal alveolar parenchyma: A
pulmonary macrophage (arrow)
lies in the central alveolus.
6
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Normal interlobular septum with
lymphatic: A lymphatic (*) courses
through an interlobular septum.
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7
Acute bronchopneumonia: The tanyellow spots centered around airways
are foci of acute bronchopneumonia,
and represent acute inflammatory
exudate in bronchi, bronchioles and
adjacent alveoli.
8&9
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Acute bronchopneumonia: Neutrophils
fill a bronchiole and adjacent alveoli.
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10
Lobar pneumonia: The entire left upper
lobe is pale and firm (consolidated),
reflecting the acute inflammatory
exudate filling virtually all airspaces.
There is focal abscess formation (box).
11
Lobar pneumonia: Alveoli are filled
diffusely by innumerable neutrophils.
12
Empyema: Suppurative exudate covers
the pleural surfaces. This exudate may
organize and form a pleural rind and
pleural adhesions that can compromise
lung expansion.
13 & 14 Lipoid pneumonia: In exogenous lipoid
pneumonia (13), aspirated oily
substances (ex: mineral oil) are
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phagocytized by macrophages whose
cytoplasm takes on a foamy
appearance. Large empty spaces (*)
represent collections of fat that did not
survive the processing steps involved
in making a glass slide. The fat
triggers fibrosis. Endogenous lipoid
pneumonia (14) is usually caused by
bronchial obstruction by a tumor or
other process, and is histologically
similar to exogenous lipoid pneumonia,
except that the large fat collections are
absent.
15
Abscess: An abscess cavity (*) is
formed by suppurative necrosis of lung
tissue, in this case caused by a
bacterial infection. Next to the
abscess, the lung parenchyma appears
consolidated (firm and tan) reflecting
the presence of pneumonia. Notice
that two small bronchi terminate in the
abscess. Communication between a
bronchus and the abscess allows foul
smelling purulent material to be
coughed up. The position of this
abscess in the right lower lobe makes
one consider aspiration as an etiology
for the abscess.
16
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Abscess: There is extensive necrosis of
lung tissue with formation of a cavity (*).
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17
Abscess: Neutrophils are mixed with
necrotic material. The giant cells raise
the possibility of aspirated material
(though none is seen in this view)
18 & 19 Respiratory syncytial virus (RSV) –
induced diffuse alveolar damage:
Alveolar septa are widened and show
prominent fibroblast proliferation.
Multinucleated giant cells characteristic
of RSV are present. The inset shows a
giant cell with an eosinophilic
intracytoplasmic inclusion.
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20
Influenza A – induced necrotizing
tracheobronchitis and diffuse alveolar
damage: The lungs are red and firm.
The tracheal and bronchial mucosa is
marked hyperemic.
21
Influenza A – induced necrotizing
tracheobronchitis: The bronchial
epithelium became completely necrotic
and was replaced by a layer of fibrin
(*). The submucosal blood vessels are
dilated.
22
Influenza A – induced diffuse alveolar
damage: Hyaline membranes,
intraalveolar and interstitial edema,
and small hemorrhages are observed.
23
Adenovirus – induced necrotizing
bronchiolitis and pneumonia: A
bronchiole and surrounding alveoli are
filled with acute inflammatory exudate.
Architectural landmarks (alveolar
septa) cannot be identified around the
bronchiole, due to necrosis.
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Pathology - Pulmonary Images
27
24
Herpes simplex virus (HSV)
pneumonia: Hemorrhagic parenchymal
nodules occur as a consequence of
viremia, usually in
immunocompromised patients. The
parenchyma shown here is necrotic,
hemorrhagic, and inflamed. The inset
shows nuclei with a "ground glass"
appearance.
Adenovirus – induced necrotizing
pneumonia: Several "smudge cells"
(circled) are present. The nuclei of
these cells are filled with basophilic
intranuclear inclusions that obscure the
nuclear envelope, hence the term
"smudge cell". The inclusions consist
of masses of virions.
25 & 26 Herpes simplex virus (HSV) – induced
ulcerative tracheobronchitis: The
bronchial epithelium has ulcerated
(near blue dots). Cells in the sloughed
epithelium have granular intranuclear
inclusions (circled). A multinucleated
giant cell (arrow), with intranuclear
inclusions within each of its nuclei, is
present. Several cells have "ground
glass" nuclei.
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28
Cytomegalovirus (CMV) pneumonia:
Four cells, probably pulmonary
macrophages, show cytologic
alterations indicative of CMV infection
(cellular and nuclear enlargement,
basophilic intranuclear inclusion, and
small intracytoplasmic inclusions).
29
Cytomegalovirus pneumonia: CMV (not
visible at this power) caused this
severe necrotizing pneumonia. The
interstitia are widened, inflamed and
necrotic. Alveolar spaces are difficult
to distinguish. The brown pigment is
hemosiderin.
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30
Pneumocystis carinii pneumonia:
Alveoli contain eosinophilic exudate
that has a honeycomb appearance.
The open spaces in the exudate are
occupied by cysts. Cysts cannot be
visualized with a hematoxylin-eosin
stain.
31
Pneumocystis carinii pneumonia [Pap
stain and silver methenamine stain
(inset)]: This view came from a
bronchoalveolar lavage sample, and
shows the characteristic exudate
associated with Pneumocystis carinii
pneumonia. The exudate has a
honeycomb appearance. Round cysts
with a central dot, characteristic of
Pneumocystis, are shown in the inset.
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cytoplasm of a macrophage, which has
since become necrotic.
32
33
Caseating granuloma (tuberculosis): A
well-circumscribed yellow nodule with a
necrotic center lies in the lung tissue.
34
Caseating granuloma (tuberculosis): A
granuloma is a collection of epithelioid
histiocytes with multinucleated giant cells
and a peripheral rim of lymphocytes. The
center of this granuloma is necrotic, with a
“cheesy” consistency that is referred to as
caseous necrosis. Caseating granulomas
are characteristic of Mycobacterium
tuberculosis infection. However, this
organism can also elicit non-necrotizing
granulomas, as well as less organized
macrophage infiltrates without
granulomas, if cellular immunity is
impaired.
35
Mycobacterium tuberculosis infection
with hilar lymphadenopathy: In the hilar
region, there is marked lymph node
enlargement and replacement by white
necrotic material (*), which represents
necrotizing granulomas caused by
tuberculosis. A Ghon focus cannot be
seen in this view.
Mycobacterium tuberculosis (acid fast
stain): This Ziehl-Neelsen stain
demonstrates numerous mycobacteria
in lung tissue. The mycobacteria are
long thin bacilli with a beaded
appearance when viewed under high
power. The clustering of some of these
bacilli reflects the fact that they
occupied and proliferated in the
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36
Postprimary tuberculosis: At the apex
of the lung, there is a pleural plaque
associated with a zone of consolidation
in the underlying lung.
37
Cavitary tuberculosis: There is a large
cavity in the inferior portion of the upper
lobe. A cavity forms when a
necrotizing granuloma(s) erodes
through a bronchial wall, and the
necrotic tissue is expectorated via a
communicating bronchus. The edges
of the cavity are lined by ragged
granulomatous material. The upper
lobe also has apical yellow/brown
consolidation, reflecting the presence
of additional granulomas.
38
Rasmussen aneurysm: A tuberculous
cavity is filled with fresh blood. The
cavity communicates with a bronchus.
The fresh blood in the cavity is a
consequence of granulomatous erosion
through the wall of a large blood vessel
with rupture of the vessel and major
hemorrhage. Blood fills the cavity,
which communicates with a bronchus,
and the blood escapes through the
bronchial system and is expectorated.
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Development of a Rasmussen
aneurysm is a relatively rare, but often
fatal, complication of tuberculosis.
39
Tuberculous pneumonia: This lobe is
extensively consolidated, due to
widespread infection of air spaces
(bronchioles and alveoli) by
Mycobacterium tuberculosis. This type
of spread is more likely when host
defenses are compromised.
Histologically, alveoli contain necrotic
material, macrophages and neutrophils,
as well as mycobacteria.
40- 42
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Miliary tuberculosis: Numerous small (2
to 3 mm) foci of granulomatous
inflammation dot the lung parenchyma.
Each of these foci contains tuberculous
bacilli. Miliary dissemination of
tuberculosis may occur within the
lungs, as well as systemically, with
involvement of any combination of
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organs. A view of liver tissue with
multiple necrotizing granulomas
(arrows) is shown (42). Miliary
dissemination usually occurs due to
spread of the organisms through the
lymphatic and/or vascular systems.
43
Tuberculous empyema: The infected
pleural space is markedly expanded
and filled with white material
representing caseating granulomas (*)
containing tuberculous bacilli, and redbrown hemorrhagic material.
Additionally, infected hilar lymph nodes
are present (white areas).
44
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Vertebral tuberculosis (Pott’s disease):
Several vertebral bodies are replaced
by white-tan granulomatous material.
A compression fracture is present.
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45
Histoplasmosis: Multiple granulomas
(arrows) are present in multiple lobes.
46
Histoplasmosis: Multiple necrotizing
granulomas are scattered throughout
this section of lung.
47
Histoplasma capsulatum (silver
methenamine stain): The tissue form of
Histoplasma is a small yeast. The
yeast reproduces by budding, which
can be seen in this view. Each of the
large clusters of yeasts represents the
contents of a single macrophage, which
has since died.
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48
Histoplasmosis: The patient from
whom this biopsy was taken had
impaired cellular immunity, and could
not produce well-formed granulomas.
Instead, his response to the fungal
infection was diffuse macrophage
infiltration of the alveolar spaces, with
smaller numbers of other inflammatory
cells. The infection could not be
contained, and spread between
alveolar spaces and through
bronchioles, like a bacterial pneumonia.
49
Histoplasmosis: In this section of a
hilar lymph node, numerous nonnecrotizing granulomas can be seen.
Granulomas associated with
histoplasmosis may be necrotizing or
non-necrotizing.
50
Cryptococcosis: Numerous yeasts are
distributed throughout the section,
appearing as round refractile bodies
with surrounding halos (clear spaces).
The inflammatory response consists
predominantly of macrophages with
smaller numbers of other inflammatory
cells.
51
Cryptococcosis (hematoxylin-eosin with
mucicarmine stain inset): Cryptococcus
neoformans usually has a mucoid
capsule. Dissolution of the capsule
during processing produces an
artifactual halo (arrows) in tissue
sections. Cryptococcus is the only
pathogenic yeast stainable in tissue
with a mucicarmine stain (red capsulesee inset).
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these fungi produce similar disease
processes in man.
55
52
Mucormycosis abscess: This necrotic
mass is an abscess, and is grossly
indistinguishable from bacterial
abscesses. However, cultures yielded
Mucor.
Angioinvasive mucormycosis: The
entire left lung is infarcted, due to
extensive vascular invasion by
mucormycosis and subsequent
pulmonary artery thrombosis. Vascular
invasion, thrombosis, and subsequent
infarction of the infected organ are
characteristic manifestations of
mucormycosis. Dissemination to other
sites also occurs via vascular channels.
This patient was markedly
immunocompromised.
53 & 54 Angioinvasive mucormycosis
(hematoxylin eosin-53, silver
methenamine-54): 53 shows a
medium-sized blood vessel in the lung
whose lumen is filled with numerous
intertwined fungal hyphae (*) admixed
with red cells. The stain for fungus
shown in 54 highlights the fungal
hyphae, which are stained black in this
preparation and can be seen in the
vessel lumen and infiltrating the vessel
wall. The hyphae are broad, irregularly
branching, and nonseptate, features
which help the surgical pathologist to
identify this fungus as a Zygomycete,
the family of fungi which includes
Mucor, Rhizopus, and Absidia. All of
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57 & 58 Aspergilloma (fungus ball): A large
aggregate of aspergillus hyphae fills a
pre-existing cavity in the lung apex.
56
Aspergillus infection (silver
methenamine stain): Aspergillus
species demonstrate thin septate
hyphae with approximate 45° angle
branching.
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59 & 60 Invasive aspergillosis: This lung from a
severely immunocompromised patient
has numerous round colonies of
fungus.
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61
Centriacinar emphysema: Air spaces
are enlarged primarily in the center of
the upper lobe. The enlarged air
spaces are associated with deposits of
carbon particles, giving the
parenchyma a darkened appearance.
Particles in tobacco smoke deposit
primarily in respiratory bronchioles,
which lie at the centers of lobules/acini.
This initiates the development of
emphysema adjacent to respiratory
bronchioles.
62
Centriacinar emphysema: This more
severe case shows more extensive air
space enlargement primarily in the
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centers of lobules, associated with
deposits of carbon particles.
63
Centriacinar emphysema: Air spaces
around the respiratory bronchiole are
enlarged, due to destruction of alveolar
septa. Note the presence of black
carbon deposits near the enlarged air
spaces.
64 & 65 Panacinar emphysema: The
parenchyma has been extensively
destroyed, with enlargement of
airspaces from the level of the
respiratory bronchiole distally (to
involve the entire acinus). Alveolar
septa are fragmented and reduced in
number.
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66
Paraseptal emphysema: Airspaces
beneath the pleura are enlarged, and
septa are fragmented.
67
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Bullous emphysema: Bullae are airfilled spaces measuring greater than 1
cm. in diam. They may be associated
with any type of emphysema.
Complications arising from bullae
include pneumothorax (from rupture of
a bulla), compression of adjacent lung,
and infection. The bulla (*) shown
measures ~ 12 cm.
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68-70
Chronic bronchitis: Though chronic
bronchitis is a clinically defined
disorder, pathologic findings associated
with it include an increase in the size of
the bronchial submucosal glands to
occupy greater than 40% of the
thickness of the bronchial submucosa,
increased mucus or mucopurulent
secretions in bronchi and bronchioles,
increased goblet cells, thickened
basement membrane, chronic
inflammation, and epithelial changes
(metaplasia, dysplasia).
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74
71
Asthma: Histologic findings in asthma
include those described above for
chronic bronchitis, and in addition,
airway smooth muscle hypertrophy and
frequently bronchial eosinophil
infiltration. The example shown
demonstrates a mixed eosinophil and
chronic inflammatory infiltrate with
overlying squamous metaplasia.
72
Mucus cast: This bronchial mucus cast
came from a patient with asthma, but
could have also come from a patient
with chronic bronchitis.
73
Allergic bronchopulmonary
aspergillosis: Amidst this abundant
mucus collection, a single aspergillus
hypha is seen (arrow).
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Churg-Strauss syndrome: Necrotizing
vasculitis (arrow) with extravascular
eosinophils (hard to discern at this
power) is present in an appendix from a
patient with asthma, peripheral blood
eosinophilia, migratory pulmonary
infiltrates, and sinusitis.
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75
Bronchiectasis, localized: Bronchi
(arrow) obstructed by a tumor (tan
mass, center) are markedly dilated
distal to the tumor.
76
Bronchiectasis, generalized: All bronchi
are markedly dilated. Bronchial
mucosae are yellow-tan and ragged,
reflecting the presence of an ongoing
suppurative infection. Proximal
bronchial walls are pale and fibrotic,
due to longstanding infection and
subsequent scarring.
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77
Bronchiectasis: The bronchial wall is
markedly inflamed. The epithelium may
be intact, as it is here, or it may be
ulcerated.
78
Squamous cell carcinoma: This “warty”
exophytic tumor (box) originated in a
proximal bronchus and has only a small
invasive component (invasive area is
not shown).
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80 & 81 Squamous cell carcinoma, well
differentiated: Large nests of
keratinizing epithelial cells with large
hyperchromatic pleomorphic nuclei
comprise this tumor. The round
aggregates of keratin are "keratin
pearls". The stroma is desmoplastic,
reflecting tumor invasion.
82
79
Carcinoma in situ: Nuclear
pleomorphism and hyperchromasia
exist throughout the full thickness of
the epithelium. Lack of maturation of
the epithelium is evident. The
process remains superficial to the
basement membrane (in situ).
Squamous cell carcinoma: This large
tumor is cavitated, a consequence of
necrosis.
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83
Squamous cell carcinoma with postobstructive pneumonia: Distal to the
tumor, the lung is pale and firm
(consolidated), corresponding to an
acute pneumonia.
84
Adenocarcinoma: This type of
neoplasm characteristically occurs in
the periphery of the lung.
85
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Adenocarcinoma: This tumor forms
complex glandular arrangements.
Glands are focally back-to-back.
Mucinous secretions are present in
glandular lumens.
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86
Adenocarcinoma: As in this example,
tumor cells are often columnar, with
variably hyperchromatic and
pleomorphic nuclei and prominent
nucleoli.
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87
Adenocarcinoma: This mucicarmine
stain reveals intracellular mucin (redpink), which indicates glandular
differentiation and is a marker for
adenocarcinomas.
88
Bronchioloalveolar carcinoma:
Bronchioloalveolar carcinoma may
present as a single or multiple discrete
nodules, or as in this slide, in a manner
resembling pneumonia.
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89 & 90 Bronchioloalveolar carcinoma: This
type of malignancy is defined by its
pattern of growth: it spreads along
alveolar septa without disrupting them,
using them as its stroma. Most of
these tumors are well differentiated,
and composed of columnar or cuboidal
epithelial cells that can contain mucin.
91
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Small cell carcinoma: This large tan
tumor originated near the hilum
(centrally) and has grown to involve
more peripheral regions of the lung as
well.
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92
Small cell carcinoma with hilar lymph
node metastases: The tan tumor
(within curved line) arose from the
contiguous bronchus and metastasized
to multiple hilar lymph nodes (arrows).
93
Small cell carcinoma metastatic to the
brain: A single well-circumscribed
hemorrhagic nodule of metastatic small
cell carcinoma is present.
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94 & 95 Small cell carcinoma: The tumor
consists of small cells with small nuclei
and high nuclear:cytoplasmic ratios
(little cytoplasm). The chromatin has a
fine “salt and pepper” appearance.
Nucleoli are not apparent.
96
Carcinoid: A polypoid intraluminal mass
(arrow) within a bronchus is a common
presentation of carcinoids. The
mucosal surface is often smooth.
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the adjacent lung tissues. Hamartomas
can arise centrally or peripherally.
97 & 98 Carcinoid: Tumor cells form nests, and
typically have uniform nuclei with little
pleomorphism, few mitoses, and a
fibrovascular stroma. The presence of
necrosis, increased mitoses, and
increased nuclear pleomorphism is
associated with a worse prognosis
(lower survival, higher frequency of
metastasis).
99
Carcinoid: This chromogranin stain is
positive (brown), indicating
neuroendocrine differentiation (as one
would expect with this tumor).
Chromogranins are located in
neurosecretory granules.
100
Hamartoma: This well-circumscribed
tan-white nodule has a lobulated
appearance and separates easily from
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104
101
Hamartoma: A combination of benign
hyaline cartilage, adipose tissue, and
fibrous tissue is present. As shown,
clefted infoldings lined by respiratory
epithelium are commonly seen.
102
Metastatic osteosarcoma: This single
metastatic nodule was resected from a
patient with a previous osteosarcoma
originating in a long bone. Bone
formation is evident.
103
Metastatic carcinoma: This is the
"cannonball" (multinodular) pattern of
metastasis.
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Metastatic carcinoma: Lymphangitic
spread of tumor is shown here (*). Two
lymphatics are filled with fragments of
tumor. Tumor spread via this route
may be extensive within the lungs.
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