lecture 28. common repratory pathological condirtion part 3
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RESPIRATORY PATHOLOGY Congenital abnormalitiesAtelectasisAcute Pulmonary Injury (eg:pulmonary oedema)
Pulmonary Infections
Obstructive Pulmonary Disease (COPD)
Restrictive (Infiltrative) Pulmonary Disease
Vascular Pulmonary Diseases
Tumors
Pathology of Common Respiratory Conditions Part [3]
OBJECTIVES
TO DISCUSS CAUSES, PATHOGENESIS, TYPES,
MORPHOLOGY,CLINICAL COURSE OF
ATELETASIS
BRONCHIETASIS
PNEUMOCONIOSIS
LEARNING OUTCOMESAt the end of this lecture student will be able to
• Define actelectasis
• Compare resorption actelectasis, compression actelectasis and
contraction actelectasis in regards predisposing factors,etiology
and morphology
• Define bronchiectasis
• Discuss the predisposing conditions ,pathogenesis,gross
µscopic morphology ,clinical course and prognosis of
bronchiectasis
• Discuss the etiology, pathogenesis, basic morphology and
pulmonary reaction and complications of occupational lungs
diseases (pneumoconiosis- anthracosis, silicosis, asbetosis)
BRONCHIECTASISpermanent dilation of bronchi and bronchioles
and is secondary to cycles of obstruction and infection
Irreversible Dilation of Bronchi and
bronchioles
Caused by Destruction of Bronchial Wall
Muscle and Elastic Elements
BRONCHIECTASIS
BRONCHIECTASIS
Associated with chronic necrotizing infection
A characteristic symptom complex
dominated by
Cough
expectoration of copious amounts of
purulent sputum
ETIOLOGY & PATHOGENESIS
Predisposing conditions
Obstruction & infection are the major
influences
Obstruction is caused byTumorsInhaled foreign bodiesMucous plugs in asthma lymph node enlargementUnder these conditions, the bronchiectasis is localized to the obstructed lung
segment
Post infectious conditions including Necrotizing pneumonia
Caused by
Bacteria ( Mycobacterium tuberculosis,
Staphylococcus aureus, Haemophilus influenzae,
Pseudomonas ) viruses ( adenovirus, influenza virus, HIV )
fungi ( Aspergillus )
Congenital or hereditary conditions Cystic fibrosis (genetic defect, abnormal viscid mucus secretion → obstruction organ passages)
Intralobar pulmonary sequestrations presence of a discrete mass of lung tissue without normal connection to the airway system
Immunodeficiency states
Primary ciliary dyskinesia
Kartagener syndrome (bronchiectasis, sinusitis, and situs inversus or partial lateralizing abnormality )
Other conditions :
rheumatoid arthritis
SLE
inflammatory bowel disease
post transplantation ( chronic lung rejection & chronic graft-versus-host disease after bone marrow transplantation)
MORPHOLOGYGross
Site :Obstructive bronchiectasis is localized to a single
segment of the lungs
Nonobstructive bronchiectasis may be localized
or generalized
Size : Airways are dilated up to 4 times normal size → sufficiently dilated that they can be followed directly out to the pleural surfacesShape : cylindrical fusiform saccular Bronchial lumens : filled with thick mucopurulent secretion
Bronchiectasis
The resected upper lobe
shows widely dilated bronchi,
with thickening of the
bronchial walls and collapse
and fibrosis of the pulmonary
parenchyma
BronchiectasisCross-section of lung demonstrating dilated bronchi extending almost to the pleura
Histology vary with activity & chronicity of the disease
In the full blown active case, intense acute & chronic inflammatory exudatesdesquamation of lining epithelium & extensive areas of necrotizing ulcerationpseudostratification of columnar cellssquamous metaplasia of remaining epitheliumabscess formation chronic case – fibrosis of bronchial and
bronchiolar walls total or subtotal obliteration of
lumen
CLINICAL FEATURES Due to accumulation of pus in dilated bronchi &
bronchiolesChronic cough with production of copious
amount of purulent sputum severe, persistent, worse in morning, induced by change in
posture, may be paroxysmal
Purulent sputum (foul-smelling) – copious amount On standing → 3 layered sputum
1st – frothy layer2nd – clear mucous layer3rd – suppurated & necrotic debris, RBC
Chronic cough with production of copious amount of purulent sputum severe, persistent, worse in morning, induced by change in posture, may be paroxysmal
Purulent sputum (foul-smelling) – copious amount On standing → 3 layered sputum1st – frothy layer2nd – clear mucous layer3rd – suppurated & necrotic debris, RBC
CLINICAL FEATURES Due to accumulation of pus in dilated bronchi & bronchioles
CLINICAL FEATURES due to inflammatory response of the lung
parenchyma & pleura
Fever → febrile episodesChest pain due to pleuritisHaemoptysis or sometimes bloody sputum caused
by rupture of thin walled vessels situated in wall of
dilated bronchioles
Other respiratory symptomsDyspnoea, orthopnoea, cyanosis,
clubbing of fingers & toes.
COMPLICATIONSLung abscess- the necrosis destroys the bronchial or
bronchiolar walls
Pneumonia – infection spread to whole lung parenchyma
Bacteremia, septicemia with metastatic
abscess formation e.g. brain abscess, meningitis
Emphysema – secondary to obstruction
Secondary amyloidosisperibronchiolar fibrosis in chronic widespread
disease → increase pressure in pulmonary circulation → Cor
pulmonale and cardiac failure
COMPLICATIONS
COMPLICATIONS
COMPLICATIONS
Chronic Diffuse Interstitial (Restrictive) Diseases
Chronic interstitial diseases are
heterogeneous group of disorders
characterized predominantly by
inflammation and fibrosis of the
pulmonary connective tissue, principally
the most peripheral and delicate interstitium in
the alveolar walls
PNEUMOCONIOSIS
Pneumoconioses are
pulmonary diseases caused by mineral
dust inhalation in workplace
The specific types of pneumoconioses are
named by the substance inhaled
(e.g., silicosis, asbestosis, anthracosis)
PNEUMOCONIOSISMineral Dust-Induced Lung Disease
Coal dust Simple coal workers' pneumoconiosis:
macules and nodules
Complicated coal workers' pneumoconiosis:
PMF
Coal mining
Silica Silicosis Sandblasting,
quarrying, mining,
stone cutting,
foundry work,
ceramics
Asbestos Asbestosis pleural effusions, pleural plaques, or
diffuse fibrosis; mesothelioma; carcinoma of the
lung and larynx
Mining, milling,
and fabrication of
ores and
materials;
installation and
removal of
insulation
Pathogenesis
The reaction of the lung to mineral dusts
depends on
size, shape, solubility, and reactivity of the
particles
PNEUMOCONIOSIS
Pathogenesis
The development of a pneumoconiosis depends on
(1) the amount of dust retained in the lung and
airways
(2) the size, shape, and buoyancy of the particles
(3) solubility and physiochemical reactivity
(4) the possible additional effects of other irritants
(e.g., concomitant tobacco smoking)
PNEUMOCONIOSIS
Pathogenesis
(1)The amount of dust retained in the lungs
is determined by
dust concentration in surrounding air
duration of exposure
effectiveness of clearance mechanisms
PNEUMOCONIOSIS
Pathogenesis
(2) the size, shape, and buoyancy of the
particles
The most dangerous particles range from
1 to 5 μm in diameter because they may reach the
terminal small airways and air sacs and settle in
their linings
PNEUMOCONIOSIS
(3)The solubility and cytotoxicity of particles
modify the nature of the pulmonary response
Smaller particles tend to cause acute lung injury
Larger particles resist dissolution and so may
persist within the lung parenchyma for years -
tend to evoke fibrosing collagenous pneumoconioses
PNEUMOCONIOSIS
Pathogenesis
The key factor in the gene-sis of
symptomatic pneumoconioses is the
capacity of inhaled dusts to stimulate
fibrosis
The pulmonary alveolar macrophage is a
key cellular element in the initiation and
perpetuation of lung injury and fibrosis
PNEUMOCONIOSIS
The more reactive particles trigger the
macrophages
to release a number of products that
mediate an inflammatory response and
initiate fibroblast proliferation and
collagen deposition
PNEUMOCONIOSIS
Pathogenesis
(4) the possible additional effects of other
irritants (e.g., concomitant tobacco
smoking)
tobacco smoking worsens the effects of
all inhaled mineral dusts
PNEUMOCONIOSIS
In simple coal workers’ pneumoco-niosis
massive amounts of dust are inhaled and engulfed by macrophages
macrophages pass into the interstitium of the lung and aggregate around the respiratory bronchioles
Pathogenesis
Pathogenesis
In silicosisthe silica particles are toxic to macrophages, which die and release a fibrogenic factorIn turn, the released silica is again phagocytosed by other macrophagesThe result is a dense fibrotic nodulethe sili-cotic nodule
Pathogenesis
Asbestosis is characterized by
little dust and much interstitial fibrosis Asbestos bodies are the classic features
PNEUMOCONIOSISCoal Workers’ Pneumoconiosis Is Due to
Inhalation of Carbon Particles
The spectrum of lung findings in coal workers is wide,
varying from
(1)asymptomatic anthracosis
(2)simple CWP with little to no pulmonary
dysfunction
(3)complicated CWP
(4)progressive massive fibrosis (PMF),
PNEUMOCONIOSIS
Morphology
Anthracosis
Accumulation of carbon particles in the
lungs (in the connective tissue along the lymphatics,
including the pleural lymphatics, or in organized lymphoid
tissue along the bronchi or in the lung hilus)
Coal Workers’ Pneumoconiosis
Morphology
Simple CWP is characterized by
coal macules (1 to 2 mm in diameter, consists of
carbon-laden macrophages)
larger coal nodules (contains small amounts of a
delicate network of collagen
located primarily adjacent to respiratory
bronchioles
Complicated CWP (progressive massive fibrosis)
is characterized by multiple
intensely blackened scars larger than 2 cm,
sometimes up to 10 cm in greatest diameter
Occur on background of simple CWP by
coalescence of coal nodules and generally
requires many years to develop
Coal Workers’ Pneumoconiosis
Microscopically
The lesions consist of dense collagen and
pigment
The center of the lesion is often necrotic,
most likely due to local ischemia
Coal Workers’ Pneumoconiosis
Clinical Course
Simple CWP
-minor impairment of lung function
Complicated CWP
-cause significant respiratory impairment
Caplan syndrome was first described as rheumatoid nod-
ules (Caplan nodules) in the lungs of coal miners
with rheumatoid arthritis
Coal Workers’ Pneumoconiosis
Silicosis Is Caused by Inhalation of Silicon Dioxide (crystalline Silica)
Silica occurs in both
crystalline and amorphous forms
crystalline forms (including quartz,
crystobalite, and tridymite) are much more
fibrogenic
After inhalation, the particles interact with
epithelial cells and macrophages
Causing
activation and release of mediators
IL-1, TNF, fibronectin, lipid mediators, oxygen-
derived free radicals, and fibrogenic cytokines
Pathogenesis
Silicosis
SIMPLE NODULAR SILICOSIS
most common form of silicosis
occur in any worker with long-term
exposure to silica
silicotic nodules less than 1 cm in
diameter (usually 2 to 4 mm)
Morphology
slowly progressing, nodular, fibrosing
pneumoconiosis
Silicotic nodules are characterized grossly in their
early stages by
tiny, barely palpable, discrete, pale-to-blackened
(if coal dust is also present) nodules in the
upper zones of the lungs
Silicotic nodules
characteristic whorled appearance, with
concentrically arranged hyalinized collagen.At the
periphery are aggregates of mononuclear cells,mostly
lymphocytes and fibroblasts.
As the disease progresses, the individual
nodules may coalesce into
hard, collagenous scars, with eventual
progression to PMF
The intervening lung parenchyma may be
compressed or overexpanded, and a
honeycomb pattern may develop
Silicosis
Fibrotic lesions may also occur in the hilar
lymph nodes and pleura
Thin sheets of calcification occur in the
lymph nodes and are seen radiographically
as eggshell calcification
Advanced silicosis (transected lung). Scarring has contracted the upper lobe into a small dark mass (arrow). Note the dense pleural thickening
Clinical Course
Simple silico-sis
does not usually lead to significant
respiratory dysfunction
Pro-gressive massive fibrosis
dyspnea on exertion and later at rest
Silicosis is associated with an increased
susceptibility to tuberculosis
Asbestos-Related Diseases
Asbestos
(Greek, “unquenchable”)
includes a group of fibrous silicate
minerals that occur as thin fibers
Asbestos is a family of crystalline hydrated
silicates that form fibers
2 forms of asbestos2 forms of asbestos
a)serpentine (i.e., curly and flexible)
b) amphibole (i.e., straight, stiff and
brittle)
Asbestosis
Asbestosis
Asbestos
Causing fibrosis by interacting with lung
macrophages
also functions as both a tumor initiator
and a promoter
Morphology
Asbestosis is marked by diffuse pulmonary interstitial fibrosis
Characterized by
the presence of asbestos bodies
which are seen as golden brown, fusiform or beaded rods with a translucent center
coated with an iron-containing proteinaceous material
Asbestosis
Asbestos body
Asbestos bodiesThese ferruginous bodies are golden brown and beaded, with a central, colorless, nonbirefringent core fiber
Pleural plaque. The dome of the diaphragm is coveredby a smooth, pearly white, nodular plaque
Asbestos-related pleural plaquesLarge, discrete fibrocalcific plaques are seen on the pleural surface of the diaphragm
Which of the following inhaled pollutants is most likely to
produce extensive pulmonary fibrosis?
(A) Silica
(B) Tobacco smoke
(C) Ozone
(D) Wood dust
(E) Carbon monoxide
(A) Silica crystals incite a fibrogenic response after ingestion by macrophages. The greater the exposure and the longer the time of exposure, the greater is the lung injury.
• A 63-year-old male worked for 20 years in the sand-
blasting business, and he used no respiratory precautions
during that time. He now has increasing dyspnea without
fever, cough, or chest pain. Which of the following
inflammatory cell types is most crucial to the development
of his underlying disease?
•(A) Plasma cell
•(B) Mast cell
•(C) Eosinophil
•(D) Macrophage
•(E) Natural killer (NK) cell
The correct answer is (D)
Silica is a major component of sand, which contains the
mineral quartz. The small silica crystals are inhaled, and
their buoyancy allows them to be carried to alveoli. There
they are ingested by macrophages, which then secrete
cytokines that recruit other inflammatory cells and
promote fibrogenesis.
Plasma cells secrete immunoglobulins, which are not a major
component of this process.
Mast cells and eosinophils are prominent in type I hypersensitivity
response.
NK lymphocytes are more likely to be a prominent component of
inflammatory processes directed against infectious agents.
A 75-year-old male experienced increasing dyspnoea. The microscopic appearance of the lung is shown here. This is most characteristic for(A) Anthracosis(B) Berylliosis(C) Silicosis(D) Calcinosis(E) Asbestosis
The answer is (E)
The ferruginous bodies shown here are long, thin crystals of asbestos that have become encrusted with iron and calcium. The inflammatory reaction incited by these crystals promotes fibrogenesis and resultant pneumoconiosis.
Berylliosis is marked by noncaseating granulomas.
Anthracosis is a benign process seen in all city dwellers as a consequence of inhaled carbonaceous dust.
Silica crystals are not covered by iron and tend to result in formation of fibrous nodules (i.e., silicotic nodules).
Calcium deposition may occur along alveolar walls with a high serum calcium (i.e., metastatic calcification).
Which of the following morphologic changes can be
seen in advanced cases of both obstructive and restrictive
lung disease?
(A) Marked medial thickening of pulmonary arterioles
(B) Destruction of elastic tissue in the alveolar walls
(C) Fibrosis of the alveolar walls
(D) Hemorrhage in the alveolar lumen
(E) Hyaline membranes lining the airspaces
The correct answer is (A) Changes of pulmonary hypertension are characteristic for restrictive and obstructive lung diseases. This explains, for example, the occurrence of cor pulmonale and right-sided CHF in persons with chronic obstructive pulmonary disease or with pneumoconiosis
Atelectasis (Collapse)
Atelectasis
Neonatal atelectasis
incomplete expansion of the lungs
Acquired atelectasis
collapse of previously inflated lung
producing areas of relatively airless
pulmonary parenchyma
Acquired atelectasis may be divided
into
Resorption (or obstruction)
Compression
Contraction atelectasis
ATELETASIS (Collapse)
Resorption atelectasis
is the consequence of
complete obstruction of an airway leads to
resorption of the oxygen trapped in the
dependent alveoli
without impairment of blood flow through the
affected alveolar walls
lung volume is diminished
the mediastinum shifts toward the atelectatic lung
ATELETASIS (Collapse)
Airway obstruction is caused by
excessive secretions (e.g., mucus plugs) or
exudates within smaller bronchi (bronchial
asthma, chronic bronchitis, bronchiectasis)
postoperative states
aspiration of foreign bodies
bronchial neoplasms (rarely)
ATELETASIS (Collapse)
Compression atelectasis
results whenever
pleural cavity is partially or completely filled by fluid exudate, tumor, blood, or air (pneumothorax)
or with tension pneumothorax, when air pressure impinges on and threatens the function of the lung and mediastinum, especially the major vessels
mediastinum shifts away from the affected lung
ATELETASIS (Collapse)
Compression atelectasis
Contraction atelectasis
occurs when
local or generalized fibrotic changes in the
lung or pleura prevent full expansion
ATELETASIS (Collapse)
reduces oxygenation
predisposes to infection
collapsed lung parenchyma can be re-
expanded (reversible disorder)
except that caused by contraction
ATELETASIS (Collapse)
ANY QUESTIONS?