Respiratory Tract Pathology Flashcards
Nasal Polyp
Occurs in CF and asprin-intolerant asthma
Nasopharyngeal Carcinoma
Malignant tumor of nasopharyngeal epithelium; Associated with EBV; Classically seen in African children and Chinese adults; Biopsy reveals pleomorphic keratin-positive epithelial cells in a background of lymphocytes; Often involves cervical lymph nodes
Acute Epiglottitis
Inflammation of epiglottis; HiB is most common cause, esp. in non-immunized children; Presents with high fever, sore throat, drooling with dysphagia, muffled voice and inspiratory stridor; Risk of airway obstruction
Croup
Inflammation of upper airway; Parainfluenza virus is most common cause; Presents with hoarse, barking cough and inspiratory stridor
Laryngeal Papilloma
Benign papillary tumor of vocal cord; Due to HPV 6 and 11; Usu single in adults and multiple in children; Present with hoarseness
Laryngeal Carcinoma
Squamous cell carcinoma usu. arising from epithelial lining of vocal cords; Alcohol and tobacco are risk factors; Presents with hoarseness, stridor, cough
Lobar Pneumonia
Characterized by consolidation of an entire lobe of lung; Most common causes are Strep. pneumo and Klebsiella pneumoniae
Gross phases:
1) Congestion - due to congested vessels and edema
2) Red hepatization - due to exudate, neutrophils and hemorrhage filling the alveolar air spaces given the spongy lung a solid consistency
3) Gray hepatization - due to degradation of red cells within the exudate
4) Resolution - type II pneumocytes regenerate air sacs
Strep. Pneumo Pneumonia
Most common cause of community acquired pneumonia in middle aged and elderly and secondary pneumonia following a viral infection.
Klebsiella Pneumo Pneumonia
Enteric flora that is aspirated; Affects malnourished and debilitated individuals esp. elderly in nursing homes, alcoholics and diabetics; Thick mucoid capsule results in gelatinous sputum (currant jelly); often complicated by abscess
Staph Aureus Pneumonia
Second most common cause of secondary pneumonia after viral infection; Often complicated by abscess or empyema (pus in pleural space)
Haemophilus Influenzae Pneumonia
Common cause of secondary pneumonia and pneumonia superimposed on COPD –> exacerbation
Pseudomonas Aeruginosa Pneumonia
Pneumonia in CF patients
Moraxella Catarrhalis Pneumonia
Community-acquired pneumonia and pneumonia superimposed on COPD
Legionella Pneumophila Pneumonia
Community-acquired pneumonia, pneumonia superimposed on COPD, or pneumonia in immunocompromised states; Transmitted from water source; Intracellular organism best visualized by silver stain
Mycoplasma Pneumonia Pneumonia
Most common cause of atypical pneumonia; Usu affects young adults (military, college); Complications include autoimmune hemolytic anemia (IgM against I antigen on RBCs – cold hemolytic anemia) and erythema multiforme; Not visible on gram stain due to lack of cell wall
Chlamydia Pneumoniae Pneumonia
Second most common cause of atypical pneumonia
RSV Pneumonia
Most common cause of atypical pneumonia in infants
CMV Pneumonia
Atypical pneumonia with post-transplant immunosuppresive therapy
Influenza Virus Pneumonia
Atypical pneumonia in elderly, immunocompromised and those with preexisting lung disease; Also increases the risk for superimposed S. Aureus or H. Influenzae bacterial pneumonia (secondary pneumonia)
Coxiella Burnetti Pneumonia
Atypical pneumonia with high fever (Q fever); seen in farmers and veterinarians (spores are deposited on cattle by ticks or are present in cattle placenta);
Is a rickettsial organism, but distinct from most because it causes pneumonia, does not require arthropod vector for transmission and does not produce a skin rash
Bronchopneumonia
Characterized by scattered patchy consolidation centered around bronchioles, often multifocal and bilateral; Caused by Staph. aureus, H. influenzae, Pseudomonas, Moraxella, Legionella
Interstitial (Atypical) Pneumonia
Characterized by diffuse interstitial infiltrates; Presents with relatively mild URTI (minimal sputum and low fever)
Caused by Mycoplasma, Chlamydia, RSV, CMV, Influenza, Coxiella
Aspiration Pneumonia
Seen in patients at risk for aspiration (alcoholics and comatose patients); Most often due to anaerobic bacteria in the oropharynx (eg. Bacteriodes, Fusobacterium, Peptococcus); Classically results in R lower lobe abscess
Primary TB
Results in focal caseating necrosis in LOWER LOBE of lung with hilar lymphadenopathy that undergo fibrosis and calcification forming a Ghon complex (subpleural)
Asymptomatic, but +PPD
Secondary TB
Reactivation commonly due to AIDS or steroids or meds that lead to immunocompromise; Occurs at APEX of lung (high oxygen tension); Forms cavitary foci of caseous necrosis; Can also lead to miliary TB or tuberculous bronchopneumonia
Clinical features: fevers, night sweats, cough with hemoptysis, weight loss
Biopsy reveals caseating granulomas and acid-fast bacilli
Pott Disease
Lumbar TB
Chronic Bronchitis
Productive cough lasting at least 3 months over a minimum of 2 years; Highly associated with smoking
Characterized by hypertrophy of bronchial mucinous glands (Reid Index >50%)
Clinical Features: productive cough, cyanosis (mucus plugs trap carbon dioxide), increased PaCO2 and decreased PaO2; increased risk of infection and cor pulmonale
Phosphatidylcholine (Lecithin)
Major component of surfactant;
Lecithin to sphingomyelin ratio is use to screen for lung maturity - a ratio of >2 indicates adequate surfactant production; Insulin decreases surfactant production (eg. Maternal diabetes)
Small Cell Carcinoma
Arises from neuroendocrine (Kulchitsky) cells; Common in Male smokers; Central location; May produce ADH or ACTH or cause Lambert-Eaton syndrome
Squamous Cell Carcinoma
Keratin pearls or intracellular bridges; Most common tumor in male smokers; Central location; May produce PTHrP
Adenocarcinoma
Glands of mucin; Most common tumor in nonsmokers and female smokers; Peripheral location; Can involve pleura
Large Cell Carcinoma
Poorly differentiated large cells; Associated with smoking; Central or peripheral
Bronchioalveolar Carcinoma
Columnar cells that grow along preexisting bronchioles and alveoli; Arise from Clara cells; Not related to smoking; Peripheral location; May present with pneumonia-like consolidation on imaging
Carcinoid Tumor
Well-differentiated neuroendocrine tumor; Chromogranin +, Not related to smoking; Classically forms a poly-like mass in bronchus; Low grade; Can cause carcinoid syndrome
Charcot-Leyden Crystals
Eosinophil-derived crystals found in asthma
Curschmann Spirals
Spiral-shaped mucus plugs found in asthma
Sarcoidosis
Restrictive lung disease; Elevated ACE; Hypercalcemia due to increased active vitamin D (1-alpha hydroxylase activity of epithelioid histiocytes converts Vit. D to its active form)
Coal Workers’ Pneumoconiosis
Diffuse fibrosis (black lung); associated with rheumatoid arthritis (Caplan syndrome); Affect upper lobes
Silicosis
Seen in sandblasters and silica miners; Fibrotic nodules in upper lobes of lung; Increased risk for TB - silica impairs macrophages and phagolysosome formation
Berylliosis
Seen in beryllium miners and aerospace industry workers; Noncaseating granulomas in the lung and hilar lymph nodes (resembles sarcoid); Increased risk for lung cancer
Asbestosis
Construction workers and plumbers and shipyard workers; Fibrosis of lung pleura with increased risk for lung carcinoma>mesothelioma; Lesions may contain long brown fibers with associated iron/ferruganous bodies
