Lung Pathology Flashcards
Infection of lung parenchyma that happens when normal defences are impaired
Presents with: fever chills, cough w/ yellow-green sputum (pus) or rusty sputum (blood), tachypnea, decreased breath sounds and dull percussions and elevated WBC
Pneumonia
Pattern of pneumonia that is seen as a consolidation that runs along the the airways mostly seem as a patchy infiltrates
Bronchopneumonia
Pneumonia pattern that is seen as consolidation of a whole lobe
Lobar pneumonia
Pneumonia pattern that has no consolidation but has inflammation of the connective tissue surrounding the alveolar sacs (more visible in lung markings)
Interstitial pneumonia
Bacteria infection usually causes which pneumonia patterns
Lobar pneumonia and bronchopneumonia
Viral infections usually cause which pneumonia pattern
Interstitial pneumonia
Consolidation of an entire lobe, usually bacterial (95% S pneumonia and klebsiella pneumonia) ~> results in currant jelly sputum
Lobar pneumonia
What are the four classic phases of lobar pneumonia
1- congestion (congested vessels and edema)
2- red hepatization ( an exudate containing neutrophils and blood filling the alveolar spaces giving solid consistency- liver like
3- grey Hepatization eventually the RBCs are broken down giving a grey appearance
4- resolution solving the exudate - healing by type 2 pneumocytes
Scattered patchy consolidation cantered around bronchioles often multifocal and bilateral
- caused by a variety of bacteria
Bronchopneumonia
1st cause of secondary pneumonia- bacterial pneumonia super imposed on a viral upper RTI for bronchopneumonia
S aureus - often complicated with abscess or empeyema (pus in pleural space)
Causes pneumonia super imposed on COPD (bronchopneumonia)
H. Influenza
Causes pneumonia in cystic fibrosis patient (bronchopneumonia)
Pseudomonas arguenosa
Pneumonia superimposed on COPD exacerbation (bronchopneumonia)
Moraxella
Community acquired super imposed on COPD or immuno compromised pneumonias l. Arise from water source, best visualised with silver stain ( bronchopneumonia)
Legionella pneumonia
This pneumonia is presented with
•diffuse interstitial infiltrates
•mild upper respiratory (minimal sputum, cough and low fever)
Interstitial (atypical) pneumonia
Most common cause of interstitial (atypical) pneumonia that usually affects young adults such as military recruits or college students living in dormitories. Can lead to autoimmune haemolytic anaemia due to IvM agains I antigens on RBCs causes cold haemolytic anemia and is not visible on gram stain due to lack of cell wall
Mycoplasma pneumonia
2nd most common cause of atypical (interstitial) pneumonia
Chlamydia pneumonia
Atypical pneumonia with post transplant immunosuppressive therapy
CMV
Atypical pneumonia in elderly, immuno compromised increases the risk for super imposed S aureus or H influenzae
Influenza virus
typical pneumonia with high fever (Q fever) seem in farmers and vets
Coxiella Burnetti
Most common cause of atypical pneumonia in infants
RSV- respiratory sensitial virus
- pneumonia in patients which are alcoholics and coma patients
- due to anaerobic bacteria in oropharynx
- results in right lower lobe abscess
Aspiration pneumonia
Inhalation of aerosolised M tuberculosis Causes
Tuberculosis
Results in focal caseating necrosis in lower lobe of the lung and hilar lymph nodes, the foci undergo fibrosis and calcification forming Ghon complex
Primary TB which arises after initial exposure (it is generally asymptotic but is PPD +)
Reactivation of ghon complex can get reactivated leading to secondary TB due to aids and it usually occurs at the apex of the lung due to higher concentration of O2 which leads to
Military pulmonary TB or tuberculous bronchopneumonia
Presents with fever night sweats cough with hemoptysis, weigh miss and on biopsy revealing caseating granulomas Also AFB stain reveals Real acid fast bacilli
Secondary TB
- airway obstruction
- Decreased forced vital capacity
- Greater decrease in forced expiratory volume 1
- decrease in FEV1:FVC ratio (key finding)
- increase in total lung capacity (air trapping)
COPD
