164: Lung Pathologies (Restrictive, Obstructive, Infectious, Tumors) Flashcards
Missing MEDIASTINAL
Which lung tumors have the best prognosis?
Carcinoid tumors
- Frequently indolent
- Usually do not metastasize
Describe the histopathology of small cell carcinoma
- Neuroendocrine differentiation
- May look like the adrenal medulla, pancreatic islets, or c-cells in the thyroid
- Nuclear moulding
- Dark uniform nuclei w/o nucleoli
- High nucleus:cytoplasm ratio (not very much cytoplasm)
- High-grade tumors
- Lots of mitotic activity and necrosis
Which part of the lugn is affected by emphysema?
Alveolated lung parenchyma
(other obstructive lung diseases affect the larger airways)
Sarcoidosis or hypersensitivity pneumonitis characteristic?
“Loose granulomas”
Hypersensitivity pneumonitis
Name the only obstructive lung disease that affects the alveolated lung parenchyma
Emphysema
Obstructive or restrictive:
“COPD, Asthma”
Obstructive
What exposure is associated wtih malignant mesothelioma?
Asbestos
Describe the gross pathology of bacterially-infected lung tissue
Firm, congested, heavier than normal (consolidated)
Parenchyma may be heaptized
Most obstructive diseases involve the ____________, while restrictive lung diseases involve the _____________.
Most* obstructive diseases involve the large airways**, while restrictive lung diseases involve the **alveolated lung parenchyma.
*excpetion: emphysema is an obstructive disease that involves the alveolated lung parenchyma
What causes bronchiectasis?
Anything that can predispose a person to obstruction of the airways
- Cystic fibrosis
- Karatagener’s syndrome
- Repeated infection
The end stage of which lung diseases is honeycomb lung?
Restrictive lung diseases
Describe the pathogenesis of acute lung injury
- Damage to pneumocytes and or endothelial cells of teh aveolar septae
- -> Inflammatory response
- -> Cytokine release
- -> Recruitment of inflammatory cells
- -> Endothelial activation
- Capillaries become leaky
- Plasma proteins accumulate in alveolar spaces
Is there a pathology present in this picture?
If so, what is it?

Sarcoidosis: well-formed granulomas

What is the prognosis of small cell carcinoma?
Bad :(
The 5-year survival rate is <5%
Obstructive or restrictive:
“Sarcoidosis”
Restrictive
What are the 3 major classifications of lung tumors?
Non-small cell
Small cell
Carcinoid
Is this lung sample normal or abnormal?
If abnormal, what pathology can you identify?

The sample is normal
UIP or NSIP characteristic:
“No granulomas”
Both
Adenocarcinoma or squamous cell carcinoma characteristic?
Keratinization
Squamous cell carcinoma
Describe the histopathology of adenocarcinoma
- Rounded gland formation
- Single layer of columnar cells
- Mucin production
- TTF1 positive
What causes emphysema?
Too many proteases and not enough antiproteases
- Proteases destroy alveolar septae in the lung parenchyma
- Conditions that result in protease/antiprotease imbalance:
- Smoking
- A1T1 deficiency
- Pre-existing lung scarring
Characteristic of which lung tumor?
High grade: lots of mitotic activity and necrosis
Small cell carcinoma
If acute lung injury does not resolve, what could it progress to?
Interstitial fibrosis with a restrictive pattern
What are the 3 categories of non-small cell lung carcinoma?
Adenocarcinoma
Squamous cell carcinoma
Larce cell carcinoma
What are the most common causes of infectious granuloma?
- Mycobacterial organisms
- TB, NTM
- Dimorphic fungi
- Blastomycosis, histoplasmosis, coccidiomycosis
Is there a pathology present in this picture?
If so, what is it?

Sarcoidosis
Shows confluent “naked” granulomas

What does the Reid index measure?
The ratio of:
Thickness of submucosal glands/
Distance between bronchial cartilage and the epithelial surface
Reid index >0.4 is consistent with chronic bronchitis
What are the most common causes of viral pneumonia in the community setting?
Influenza A and B
RSV
Adenovirus
hMPV
What are the two major categories of obstructive lung disease?
- COPD
- Emphysema
- Chronic bronchitis
- Asthma
What has a better prognosis: Idiopathic UIP or idiopathic NSIP?
Idiopathic NSIP
Idiopathic UIP = IPF, median survival is 3 years
How does smoking lead to emphysema?
Smoking causes an increase in protease secretion by inflammatory cells and inactivation of antiproteases due to tobacco smoke
Too many proteases = destruction of alveolar septae
-> enlargement of lung spaces -> emphysema
What is TTF1? How can it aid the diagnosis of lung cancer?
TTF1 is a protein produced by adenocarcinomas
It is specific for adenocarcinomas of the lung
What are the most common causes of bacterial pneumonia in healthy patients in the community setting?
- Streptococcus pneumoniae*
- Haemophilus influenzae*
- Moraxella catarrhalis*
- Staphylococcus aureus*
Long-term, chronic hypersensitivity pneumonitis shows a _________ pattern on HRCT.
Long-term, chronic hypersensitivity pneumonitis shows a UIP pattern on HRCT.
Atopic or non-atopic asthma characteristic?
“Trigger = airway irritation due to exercise, cold air, inhaled irritants, or viral infection”
Non-atopic asthma
Obstructive or restrictive characteristic:
“Increased lung capacity”
Obstructive
Obstructive or restrictive characteristic:
“Rapid expiration of air”
Restrictive
Sarcoidosis or hypersensitivity pneumonitis characteristic?
“Lymphoplasmacystic inflammation”
Hypersensitivity pneumonitis
Chronic Bronchitis or Asthma characteristic?
“Medial therapy can restore normal physiology”
Asthma
UIP or NSIP characteristic:
“Sub-pleural, basilar predominance”
UIP
What is the most common form of lung cancer?
Adeonocarcinoma
(a type of non-small cell lung carcinoma)
Atopic or non-atopic asthma characteristic?
“Type 1 IgE hypersensitivity reaction”
Atopic
Characteristic of which lung tumor?
Low nucleus:cytoplasm ratio
Carcinoid tumor
What is the prognosis for malignant mestothelioma?
<2 year median survival :(
Describe the key features of sarcoidosis
-
Non-necrotizing granulomatous inflammation
- Well-formed
- No lymphocytic inflammation
- Upper-lobe predominant
- Idiopathic, systemic granulomatous disease
- Must rule out infectious etiology to diagnose sarcoidosis
What pathologic changes are seen in chronic bronchitis?
- Mucus glad hypertrophy
- More mucus cells in the bronchial epithelium
- Increased thickness of the bronchial mucus glands
- Chronic inflammatory infiltrate
- Lots of lymphocytes and macrophages
Sarcoidosis or hypersensitivity pneumonitis characteristic?
“Associated with infectious etiology”
Neither
Sarcoidosis = idiopathic
Hypersensitivity pneumonitis = exposure to organic antigens
UIP or NSIP characteristic:
“Temporally and geographically heterogeneous fibrosis”
UIP
Describe the histology of squamous cell carcinoma
- Keratinization
- Abundant dense, pink cytoplasm
- Intracellular bridges (desmosomes) between squamous cells
- TTF1 negative
Describe the pathologic findings of viral pneumonia
- Increased lymphocytes and plasma cells in alveolar septae and interstitium
- Hyaline membrane and neutrophils may be present if very severe
Describe the histopathology of bacterial pneumonia
- Many neutrophils in alveolar spaces
- Other inflammatory cells may be present too
- Congestion of capillaries of aleolar septae
- Hyaline membranes possible
Obstructive or restrictive characteristic:
“Difficulty expiring air”
Obstructive
Adenocarcinoma or squamous cell carcinoma characteristic?
TTF1 negative
Squamous cell carcinoma
Chronic Bronchitis or Asthma characteristic?
“Eosinophilic infiltrate”
Asthma
Describe the characterisitics of chronic asthma
Basement membrane thickening
Smooth muscle hypertrophy and hyperplasia
Goblet cell (mucus gland) hyperplasia
Which non-small cell lung carcinoma is most strongly associated with a history of smoking?
Squamous cell carcinoma
Atopic or non-atopic asthma characteristic?
“Trigger = environmental allergen”
Atopic asthma
Obstructive or restrictive characteristic:
“End stage = honeycomb lung”
Restrictive
Characteristic of which lung tumor?
Keratinization
Squamous cell carcinoma (non-small cell)
What is the underlying pathology of asthma?
Chronic inflammation
- Surrounds the larger and smaller airways
- Inflammatory infiltrate contains eosinophils, Th2 lymphocytes, leukotrienes
What is status asthmaticus?
Severe acute asthma
Attacks wtihout return to normal - can be fatal
Sarcoidosis or hypersensitivity pneumonitis characteristic?
“Presents with fever and cough”
Hypersensitivity penumonitis
Obstructive or restrictive characteristic:
“Increased elastic recoil of the lung parenchyma”
Restrictive
UIP or NSIP characteristic:
“Microcscopic honeycombing may be present”
UIP
Which lung cancers occur most commonly in smokers?
Squamous cell carcinoma (non-small cell)
Small cell carcinoma
What are the pathologic findings of acute lung injury?
Diffuse alvolar damage (DAD)
- Intra-alveolar dense, pink hyaline membrane
- Made up of necrotic cells + fibers + plasma proteins
- High numbers of inflammatory cells
What etiologies are associated with an NSIP pattern?
- Autoimmune
- Connective tissue disease
- Idiopathic
What is bronchiectasis?
Irreversible dilation of the airways
- Airways are bigger than the accompanying blood vessel
- Walls are repeatedly destroyed and hollowed out
- Bronchi become plugged wtih mucus containing acute and chronic inflammatory cells
- Not a disease, but a process that can complicate other diseases
- Ex: Cystic Fibrosis
What defines chronic bronchitis?
A productive cough on most days in 3 consecutive months of 2 consecutive years
Adenocarcinoma or squamous cell carcinoma characteristic?
TTF1 positive
Adenocarcinoma
Describe the viscious cycle of bronchiectasis
Obstruction due to inflammation -> Infection -> Bronchial wall destruction -> Rinse and repeate
Where are mesothelial cells located?
They line the pleural and peritoneal cavites
Characteristic of which lung tumor?
Mitotic figures and necrosis are rare
Carcinoid tumors
Obstructive or restrictive characteristic:
“Fibrosis, diffuse inflammatory infiltrate”
Restrictive
What cells are common in the infiltrate of a person with infectious granulomas?
Lymphocytic infiltrate
UIP or NSIP characteristic:
“Temporally and geographically uniform fibrosis”
NSIP
Is there a pathology present in this picture?
If so, what is it?

UIP
Shows geographic and temporal heterogeneity

Describe the key features of acute or subacute hypersensitivity pneumonitis
- Loose/poorly-formed granulomas
- Lymphoplasmacystic infiltrate
- Associated with exposure to organic antigens
- Animals, plants, bacteria
- Special stains and cultures required for diagnosis
Describe the key features of chronic hypersensitivity pneumonitis
UIP pattern
- Honeycombing
- Geographically and temporally heterogeneous fibrosis
What etiologies are associated wtih a UIP pattern of lung disease?
- Autoimmune
- Asbestos exposure
- Hypersensitivity
- IPF if all else is ruled out
Adenocarcinoma or squamous cell carcinoma characteristic?
Mucin production
Adenocarcinoma
Obstructive or restrictive characteristic:
“Decreased lung capacity”
Restrictive
Charcot Leyden crystals are seen in which airway pathology?
Asthma
Charcot leyden crystals are formed from the products of eosinophil degradation
Is there a pathology present in this picture?
If so, what is it?

This is a normal lung!

Adenocarcinoma or squamous cell carcinoma characteristic?
Single layer of columnar cells
Adenocarcinoma
Describe the histopathology of carcinoid tumors
- Neuroendocrine differentiation
- Nested/cord-like growth pattern
- Abundant cytoplasm
- Nuclei are bland with granular “salt and pepper” chromatin
- Mitotic figures and necrosis are rare (because they are indolent, very slow growing)
What is the most common cause of bacterial pneumonia in cystic fibrosis?
Pseudomonas aeruginosa
What are the characteristic findings of pneumonia caused by Herpes viruses?
- Pale glassy chromatin
- Nuclear moulding
- Multinucleation
- Margination of chromatin

Chronic Bronchitis or Asthma characteristic?
“Infiltrate contains lots of lymphocytes and macrophages”
Chronic bronchitis
Viral pneumonia caused by which viruses is usually only seen in immunocompromised patients?
CMV
Herpes viruses
Describe the key features of a Usual Interstitial Pneumonia (UIP) pattern
-
Fibrosis: Temporally and geographically heterogeneous
- Fibrosis and normal lung may be adjacent
- Mature and less mature fibrosis may be adjacent
- Sub-pleural predominance
- Basilar predominance
- No granulomas
Obstructive or restrictive characteristic:
“Decreased elastic recoil of the lung parenchyma”
Obstructive
Characteristic of which lung tumor?
Neuroendocrine differentiation
Small cell carcinoma
Carcinoid tumor
Describe the key features of a Nonspecific Interstitial Pneumonia (NSIP) pattern
- Fibrosis: Temporally and geographically uniform
- No granulomas
Sarcoidosis or hypersensitivity pneumonitis characteristic?
“Well-formed, tightly-packed granulomas”
Sarcoidosis
What are the most common causes of bacterial pneumonia in the hospital setting?
- Staphylococcus aureus*
- Gram negative enteric bacteria*
How is large cell carcinoma diagnosed?
By excluding squamous cell carcinoma and adenocarcinoma
Large cell carcinoma tumors are poorly differentiated, and they do not have features of adenocarcinoma, squamous cell carcinoma, or small cell carcinoma
Describe the presentation of bronchiectasis
Chronic productive cough with foul-smelling sputum
Describe the gross pathology of bronchiectasis
Large airspaces in the periphery of the lung
(normally, you would only find large airspaces centrally)
What is the difference between bronchopneumonia and lobar penumonia?
- Bronchopneumonia has a patchy distribution
- Lobar pneumonia has a confluent pattern, may infect the entire lung
Characteristic of which lung tumor?
High nucleus:cytoplasm ratio
Small cell carcinoma
Describe the gross pathology of malignant mesothelioma
Thick, pale, fibrous rind around normal lung parenchyma
Is there a pathology present in this picture?
If so, what is it?

NSIP
Shows uniform fibrosis

What are the characteristic findings of pneumonia caused by CMV?
Intranuclear “owl eye” inclusions
Usually only immunocompromised patients have pneumonia caused by CMV

Almost all cases of chronic bronchitis are related to _______
Almost all cases of chronic bronchitis are related to smoking