Lung Pathology Flashcards
Pathogenesis of asthma
Sensitisation to allergen; followed by…
Immediate phase = mast cell degranulation mediator release inc. vascular permeability, eosinophil and mast cell recruitment and bronchospasm
Late phase = tissue damage, increased mucous production, muscle hypertrophy
Histology of asthma
Hyperaemia
[Top right] Eosinophils and goblet cell hyperplasia
Hypertrophic constricted muscle
Mucus plugging and inflammation
Histology of COPD
Dilatation of airways
Hypertrophy of mucous glands
Goblet cell hyperplasia
Causes of bronchiectasis
Congenital (CF, ciliary dyskinesia
Inflammatory (post-infectious, obstruction, 2nd to bronchiolar disease and interstitial fibrosis, asthma)
Histoogy of pulmonary oedema
Intra-alveolar fluid on histology
“Heart failure cells” = iron-laden macrophages (right)
Pathology of ARDS
- Capillary congestion
- Exudative phase
- Hyaline membranes
- Organising phase
Bronchopneumonia pathology
Patchy bronchial and peribronchial distribution, lower lobes, inflammation surrounding the airways themselves and is within the alveoli
Lobar pneumonia pathology
- (1) Congestion Hyperaemia, Intra-alveolar fluid
- (2) Red hepatization Hyperaemia, Intra-alveolar neutrophils (non-atypical)
- (3) Grey hepatization (looks like liver) Intra-alveolar connective tissue
- (4) Resolution Restoration normal architecture
90-95% pneumococci (i.e. strep)
Inflammation in atypical pneumonias
Interstitial inflammation without the accumulation of intra-alveolar inflammatory cells
Pathogenesis of emphysema
Cigarette smoke inhibits A1AT- causes proteases to degrade the tissue causing permanent loss of alveolar parenchyma distal to terminal bronchiole
Causes of granuloma
TB, sarcoidosis, FB aspiration
Sarcoidosis lung involvement
discrete epithelioid and giant cell granulomas, preferential distribution in upper zones with a tendency to peri-lymphatic and peri-bronchial advanced disease becomes fibrocystic
Diagnosis of sarcoidosis
non-caseating granuloma, elevated serum ACE, hypercalcaemia (1a-hydroxylase)
Types of fibrosis interstitial lung disease
Idiopathathic pulmonary fibrosis
Extrinsic allergic alveolitis
Pneumoconiosis
IPF pathology
- Macro = basal and peripheral fibrosis and cyst formation
* Micro = interstitial fibrosis (varying stages)
Diagnosis of IPF
HR-CT ± biopsy diagnosis
Which lung cancers are associated with smoking
Squamous cell carcinoma
Small cell carcinoma
Large cell
Which lung cancer is not associated with smoking
Adenocarcnioma
Features of Squamous CC
Centrally located arising from bronchial epithelium spread locally metastasise late
Features of adenocarcinoma
o Peripheral (terminal airways) with multi-centric pattern o Precursor lesion: atypical adenomatous hyperplasia
In smokers, the main mutations are K-ras, issues with DNA methylation and p53
In non-smokers, EGFR mutations are very important (these are drug targets)
o Extra-thoracic metastases are COMMON and occur EARLY (80% present with metastases
Histology of adenocarcinoma
Gland formation
Papillae formation
Mucin
Histology of large cell carcinoma
o Poorly differentiated tumours composed of large cells
Features of small cell carcinoma
Often CENTRAL and near the bronchi
80% will present with advanced disease very chemosensitive but VERY POOR PROGNOSIS
May cause paraneoplastic syndromes (i.e. SIADH)
Histology of small CC
Small poorly differentiated cells Common mutations: p53, RB1 o Cytology: Small cells Ciliated normal respiratory cell
Adenocarcinoma molecular targets
- EGFR mutation (responder or resistance)
- ALK translocation responds to Crizotinib
- Ros1 translocatio
Paraneoplastic conditions associated with lung cancer
ADH, ACTH, PTH
