Respiratory pathology Flashcards
waiting for update (current stage: pneumonia)
3 Pathological classifications of pneumonia
lobar pneumonia, bronchopneumonia, interstitial pneumonia
Inflammatory cells & pathogen types of broncho-/ lobar pneumonia
polymorphs, then macrophages. bacteria, fungi
Inflammatory cells & pathogen types of interstitial pneumonia
lymphocytes. virus, protozoa, mycoplasma
4 stages of gross pathology of lobar pneumonia (time)
congestion (24 hours) –> red hepatisation (2~4 days) –> grey hepatisation (4~8 days) –> fibrosis
2 phases of histological pathology of lobar pneumonia
acute phase –> organizing phase
Most common bacteria in acute exacerbation of COPD
Hemophilus influenzae
Most common bacteria in secondary infection to viral infection
S. aureus
Bacteria of atypical pneumonia
Legionella pneumophila, Mycoplasma pneumoniae, Chlamydia pneumoniae
Which pneumonia shows interstitial inflammation and diffuse alveolar damage?
atypical pneumonia
Which atypical pneumonia shows multinucleated pneumocytes?
SARS
Which atypical pneumonia presents with hemophagocytic syndrome?
Avian flu (Influenza A H5N1)
Pathogenesis of Ghon focus (time)
type IV HSR (3 weeks)
Histology of Ghon focus
- central caseous necrosis
- surrounded by epithelioid histiocytes & Langhans giant cells
- further rimmed by lymphocytes
How is Ghon complex different from Ghon focus?
Ghon complex = Ghon focus + hilar lymph nodes
How is Ranke complex different from Ghon complex?
Ranke complex = calcified Ghon complex
Pancoast syndrome (3)
- small hand muscle wasting, numbness, weakness
- Horner’s syndrome
- hoarseness of voice
Paraneoplastic manifestations in lung cancer (3+3)
- SIADH, Cushing, HHM [SQCC]
- Lambert-Eaton myasthenic syndrome, dermatomyositis, hypertrophic pulmonary osteoarthropathy
Which lung cancer could present with HHM?
SQCC
Lung cancers (5)
ADC (MC), SQCC, LCLC, SCLC, carcinoid
Origin of lung carcinoma
bronchial epithelial cells
Genetic associations with lung carcinoma (4)
- EGFR (MC), ALK, ROS1
- KRAS (emerging)
(HER2, BRAF, RET)
5 growth patterns of lung ADC (poorest prognosis?)
lepidic, acinar, papillary, micro-papillary (poorest), solid
Pathology of lung ADC (2)
intracellular mucin, desmoplastic reaction
Progression of lung ADC
atypical adenomatous hyperplasia (AAH) –> adenomatous in situ –> minimally invasive ADC –> invasive ADC
minimally invasive adenocarcinoma in lungs definition (2) (what is the prognosis?)
<=3cm in diameter, invasion <5mm in depth
~100% survival
Lung cancer with the strongest association with smoking
SQCC
Pathology of lung SQCC (3)
- central in major bronchi
- keratin
- intercellular bridges
Progression of lung SQCC
squamous metaplasia –> squamous dysplasia –> SQCC in situ –> SQCC
lung cancer with the poorest survival
SCLC
Pathology of lung SCLC (6)
- centrally located
- oat cell (nucleus: hyperchromatic, fine chromatin, inconspicuous nucleoli, high mitosis)
- nuclear moulding
- Azzopardi effect
- NE markers +ve
- electron-dense granules under electron microscopy
Diagnosis of lung LCLC
by exclusion
Lung carcinoid tumour: typical vs atypical
typical (more benign), atypical (more malignant)
Pathology of lung carcinoid tumour (2)
organoid architecture, NE markers +ve
Risk factor of mesothelioma
Asbestos
Precursor lesions of mesothelioma (2)
extensive pleural fibrosis, plaque
Patterns of mesothelioma (3)
epithelial, sarcomatoid, biphasic
How to differentiate between obstructive and restrictive lung diseases?
spirometry: FEV1/FVC
Complications of COPD
- acute exacerbation
- pneumothorax
- cor pulmonale
- secondary polycythaemia
- respiratory failure (type II)
What is chronic bronchitis?
persistent productive cough for >=3 months in >=2 consecutive years
Pathogenesis of chronic bronchitis
goblet cell metaplasia –> mucus hypersecretion –> inflammation, fibrosis
Pathological index for chronic bronchitis
Reid index >0.4
(Thickness of mucosal glands / thickness of bronchial wall)
What is emphysema?
abnormal permenant enlargment of airspaces distal to terminal bronchioles accompanied by destruction of their walls without obvious fibrosis
Which protein deficiency is related to emphysema? Explain. Also explain how it is related to tobacco
α1-antitrypsin
AAT deficiency –> ↑ neutrophil elastase –> attack pulmonary elastic tissues
ROS in tobacco –> deplete antioxidant mechanisms –> inactivate AAT
4 Types of emphysema. Compare the common two (5)
centriacinar, panacinar, distal acinar, irregular
Centriacinar vs panacinar:
- Aetiology: air-related; AAT deficiency
- Distribution: respiratory bronchioles; acini
- Lung regions: upper lobes; lower lobes
- V/Q: ↓ ; ~
- ABG changes: severe; less
What is asthma?
recurrent episodes of wheezing, cough, dyspnoea, chest tightness
2 types of asthma
extrinsic / atopic v.s. intrinsic
Aetiology of bronchiectasis (6)
- Congenital
- Infection (MC)
- Bronchial obstruction
- Fibrosis (traction bronchiectasis)
- Autoimmune
- Idiopathic
Aetiology of interstitial lung disease (6) (sites)
Idiopathic, autoimmune, inhaled agents, infiltrative, infection, iatrogenic
- Idiopathic (basal)
- Autoimmune (basal except AS, psoriasis)
- Inhaled agents (apical except asbestos)
- Infiltrative (apical)
- Infection (apical)
- Iatrogenic (radiation apical, drugs basal)
7 Pathological examples of interstital lung disease
Fibrosing:
- UIP
- BOOP
- Pneumoconiosis
- asbestosis
Granulomatous:
- sarcoidosis
Other:
- DIP
- PAP
ILD with alveoli full of brown macrophages
Desquamative interstitial pneumonia
ILD with alveoli full of PAS+ protein
Pulmonary alveolar proteinosis
ILD associated with TGF-β1
Usual interstitial pneumonia
ILD associated with smoking
Desquamative interstitial pneumonia
ILD with spatial heterogenicity
Usual interstitial pneumonia
ILD with homogenic lesion
Cryptogenic organizing pneumonia / Bronchiolitis obliterans with organizing pneumonia
Targeted therapy to EGFR+ lung ADC (2)
Erlotinib 厄洛替尼, Gefitinib 吉非替尼
Tests for EGFR, ALK, ROS1, KRAS, PD-L1
PCR: EGFR, ALK, ROS1, KRAS
IHC: PD-L1
3 phases of ARDS
Exudative ==> Proliferative ==> Fibrotic
Pathology of ARDS (3)
diffuse alveolar damage
hyaline membrane formation in alveolar walls
pulmonary oedema / exudate
Which IHC marker is used to differentiate between lung SQCC and ADC with solid pattern?
P40