Pathology - Resp Flashcards
List 6 causes of ALI or ARDS:
Infection, trauma (inc. fat embolism), toxic exposure, pancreatitis, uraemia, and immune reactions.
What are “heart failure” cells?
Haemosiderin-laden macrophages which occur with chronic congestion and are therefore indicative of heart failure.
Overall mortality rate in ARDS?
Compared to AIP?
40% compared with 50% in AIP, which is essentially ARDS with no identifiable cause.
What are the anatomical classifications of emphysema and what are the associated conditions/risk factors?
Centriacinar - heavy smokers
Panacinar - A1 anti-trypsin def
Distal acinar - near peripheral fibrosis.
Neutrophils mediate emphysema by releasing cellular proteases. Name them:
Elastase
Proteinase-3
Cathepsin-G
Why do NSAIDS trigger asthma?
These agents inhibit COX (without affecting LOX) and therefore tip the balance of arichidonic acid metabolism towards bronchoconstrictor leukotrienes.
Describe the acute, late, and remodelling phases of asthma:
Acute - IgE coated mast cells cause primary (leukotriene) and secondary (cytokine) mediator release which cause bronchospasm, oedema, mucus secretion, and leukocyte recruitment.
Late - mediated by leucocytes, this is characterised by persistent spasm and oedema with infiltration and epithelial loss.
Remodelling occurs due to SMC and mucus gland hypertrophy, increased vascularity, and increased collagen.
What is the most dangerous size bracket for respiratory particles?
Why?
1-5 micrometers. These particles can reach the terminal alveoli and settle in the lungs.
What is the hallmark of sarcoidosis?
3 histological features
Non-caseating granulomas.
Schaumann bodies and asteroid bodies commonly occur but are not pathognomonic.
Sarcoidosis is a diagnosis of…
Exclusion.
What is Loeffler’s syndrome?
Simple pulmonary eosinophilia.
95% of PE comes from DVT.
What are the other 5% from?
Pulmonary HTN
Pulmonary atherosclerosis
Heart failure
How frequent is pulmonary infarction in PE? Why is this? Who is at risk?
Occurs ~10%
Occurs in patients with heart failure as these patients fail to supply the tissue via the bronchial arteries.
What is the most common serotype of H. influenzae to cause pneumonia?
Serotype B (A-F).
Classification and virulence factors of H. influenzae?
Gram negative, encapsulated, pleomorphic organism.
Adhesive pili, a factor that dysregulates ciliary beating, and an IgA protease.
What is the most common Gram Negative pneumonia?
Klebsiella. Especially common in alcoholics.
H. influenzae more commonly affects children and patients with COPD.
What are the 4 stages of lobar pneumonia?
- Congestion
- Red hepatization
- Grey hepatization
- Resolution.
Asbestos + smoking =
50-90 fold increase in risk of lung cancers.
Broad statements on SCC versus NSCC?
Small cell is metastatic at diagnosis with an initially high response to chemoradiation.
Non-small cell is les often metastatic but has a poorer response to treatment.
Types and approximate frequencies of lung cancer?
Adenocarcinoma ~37%m 47%f
Squamous ~32%m 25%f
Small cell ~14%m 18%f
Which subset of lung cancer is NOT associated with smoking?
Which is most closely associated with smoking?
Bronchioalveolar carcinoma.
Squamous cell carcinoma.
Paraneoplastic syndromes occur in 1-10% of tumours. What are the causative substances?
ADH = SIADH ACTH = Cushings PTH = Hypercalcaemia Calcitonin = Hypocalcaemia Gonadotropins = Gynaecomastia Serotonin = Carcinoid.
Asbestos disease may manifest as:
Localised plaques and effusions
Parenchymal disease (asbestosis)
Lung carcinoma, malignant mesothelioma, laryngeal and other neoplasms.
What are the two types of asbestos?
Straight stiff amphiboles reach the deep lung more readily than serpentine fibres, accounting for the former’s greater pathogenicity.
What are asbestos bodies?
Ingested asbestos fibres, coated by iron containing material to form characteristic beaded, dumbbell shaped fibres that distinguish asbestosis from other disorders.
What are the two common pre-cancerous lesions in the oral cavity?
Leukoplakia, occur in 3% of people; 5-25% of which are premalignant.
Erythroplakia, less common but more ominous.
Most oral cancers are?
Overall 5-year survival?
95% are SCC
50% (early 80%; late 19%)
50% of oropharyngeal cancers harbour which virus?
HPV
Patients with HPV associated cancers fare better.
Risk factors for oral SCC beyond smoking, drinking, and HPV?
Pipe smoking
Betal nut and paan chewing
Actinic radiation
Family history.
Nasopharyngeal carcinoma is associated with which virus?
Who does it affect?
Prognosis?
EBV
Children in Africa. Adults in southern China.
70% have nodes at presentation. 3-year survival is 50-70% with radiotherapy.
Carotid body tumours are what?
Paragangliomas. Typically occur in patients between 50-70.
Complications of xerostomia include?
Increased caries
Candidiasis
Difficulty swallowing
Difficulty taking.
What is a ranula?
A mucocoele of the SUBLINGUAL gland.
Sialadenitis is most commonly caused by which bacteria?
S. aureus or Strep. viridians
What are pleomorphic adenomas?
What proportion of parotid tumours do they constitute?
What is their malignant potential?
Painless, slow growing, mobile, discrete benign tumours of mixed epithelial and mesenchymal differentiation.
Malignant transformation occurs in 10% after 15 years duration. 30-50% 5-year mortality if malignant.
Which group is at risk for Warthin’s tumours?
Smokers are 8 times more likely to get this benign tumour.
What is the most common primary malignancy of salivary glands?
Mucoepidermoid carcinoma.
15% of all salivary gland neoplasms. Poorly defined, 50% 5 year survival and high recurrence rates.
