Histopath of Pulmonary Diseases Flashcards
What are the 2 major clinical forms of asthma that can overlap?
- Extrinsic asthma
- Intrinsic asthma
Describe Extrinsic Asthma
- association with atopy (allergies) mediated by type 1 hypersensitivity
- asthmatic attacks are precipitated by contact with inhaled allergens
- occurs most often in childhood
Describe Intrinsic Asthma
- attacks precipitated by respiratory infections, exposure to cold, exercise, stress, inhaled irritants and drugs (aspirin)
- most often affects adults
Describe histology of Emphysema
- large bullae apparent on surface of lungs
- thick yellow/tan purulent exudate
- pleural cavity is filled with purulent exudate
- loss of alveolar walls & remaining airspaces are dilated
Describe Bullae
- Bullae = large dilated airspaces that bulge out from beneath the pleura
What does emphysema give rise to?
- a slowing of forced expiration
Describe Bronchiectasis
- airways of the lungs become widened
- buildup of excess mucus
- make the lungs more vulnerable to infection
Describe hallmarks of Chronic Bronchitis
- hypersecretion of mucous in large airways
- mostly due to obstruction & infection
Describe the Histology of Bronchiectasis
- dilated bronchi
- repeated episodes of inflammation result in scarring leading to fibrous adhesions between lobes
Describe the histology of Aspergillosis
- fungal granuloma produces by aspergillus organism
- acutely branching dark blue elongated hyphae of Aspergillus
What bacteria are associated with Chronic Sinusitis ?
- Streptococcus pneumoniae
- Hemophilus influenzae
Describe the Histology of TB
- small tan-yellow sub-pleural granulomas
- ‘Ghon complex’ characteristic gross appearance with primary TB
- granulomas can decrease in size over time & can also calcify
- scattered tan granulomas are present over surface
- extensive caseation (dry, cheese like mass)
What stain can be used for TB ?
- Acid fast bacilli is done (AFB stain) to find the mycobacteria in the tissue section
What is TB characterised by?
- Reactivation, not reinfection
Where is the most common site of primary TB ?
Lower zone of the upper lobe
What are the most common cuases for viral pneumoia ?
- influenza A & B
- adenovirus
- RSV (children typically)
What does RSV stand for?
Respiratory Syncytial Virus
Describe the Histology of RSV
- giant cells are part of viral cytopathic effect
- inset is typical giant cell-round & pink intracytoplasmic inclusion
Describe the histology of Lobar pneumonia
- pattern of patchy distribution of bronchopneumonia is seen
- typically a ‘hospital acquired’ pneumonia
Describe the histology of Bronchopneumonia
- abscesses irregular, rough-surfaced walls seen within areas of tan consolidation
- lung abscesses, if large enough, will contain liquefied necrotic material
- purulent exudate often results in an air-fluid level by chest radiograph in abscess
- areas of lighter tan consolidation
What morphological changes are present in Lobar pneumonia ?
- morphological changes of red to grey hepatisation
What is the dominant characteristic of bronchopneumonia ?
- patchy consolidation of lungs
Describe Pulmonary
Vascular Disease
- saddle embolus bridges across pulmonary artery from heart as it divides into right & left main pulmonary arteries
- saddle embolus is cause for sudden death
Define Sarcoidosis
pulmonary interstitial fibrosis
