Pulm Path Pt 2 Flashcards
What does idiopathic pulmonary fibrosis lead to?
IPF damages pulmonary tissue with waves of inflammatory injury leading to fibrosis
What presents as:
- basilar infiltrates -> “honeycomb lung”
- dyspnea
- crackles on auscultation
IPF
What are the contributing factors of IPF?
- environmental: industrialized societies, smoking
- genetic factors
- increasing age (>50)
What is expected on pulmonary biopsy of IPF?
- normal areas
- inflammation
- fibroblast foci
- peripheral honeycombing
What are the potential therapies of IPF?
- lung transplantation
- medication to arrest fibrosis: tyrosine kinase inhibitors, TGFb inhibitors
Why does non-specific interstitial pneumonia (NSIP) have a much better prognosis than IPF?
It is more diffuse
- NOT non-specific
- uniform infiltrates and fibrosis
- no heterogeneity
- no fibroblast foci
- no granulomata
50-60 year old patient presents with pneumonia-like consolidation
- fibroblast foci, aka Masson bodies (organizing plugs of connective tissue that look like cotton candy)
Cryptogenic Organizing Pneumonia (COP)
What can be given to control COP?
excellent prognosis (full recovery) with oral steroid**
Why is COP a diagnosis of exclusion?
it is not infection, drug or toxin-induced, or related to connective tissue disorders
What are the three autoimmune/connective tissue diseases that can manifest as Interstitial Lung Disease (ILD)?
- Rheumatoid arthitis
- Systemic sclerosis
- Lupus erythematosus
What is prognosis linked to in ILD?
treatment of the underlying condition
What does sarcoidosis manifest as?
** non-caseating (non-necrotizing)** granulomata
African American pt, less than 40 years old, with incidental abnormal radiograph or dyspnea
- elevated serum ACE levels
sarcoidosis
- likely immune-related etiology, possible genetic predisposition
- death may occur from pulmonary, cardiac, or neurologic involvement
BERNIE MAC
What are the 5 stages of sarcoidosis on the basis of chest radiographs?
Stage 0: no abnormalities Stage 1: lymphadenopathy Stage 2: lymphadenopathy + pulmonary infiltration Stage 3: pulmonary infiltration Stage 4: fibrosis
NOTE: stages do not always occur in order, 20% of patients have progressive lung disease
If you see an Asteroid body or Schaumann bodies on a histo slide, what should you always think of?
sarcoidosis
What is hypersensitivity pneumonitis?
immune reaction to inhaled antigen
Pigeon-breeder’s lung, farmer’s lung and hot tub ling are all examples of what?
hypersensitivity pneumonitis
What does the diagnosis of hypersensitivity pneumonitis require?
thorough history!!!!
When would you see an AIRWAY-centered granulomata with associated lymphocytes?
hypersensitivity pneumonitis
40-50 year old patient, smoker, presents with restrictive lung disease
- histology shows very characteristic “stuffed” alveolar spaces full of macrophages
Desquamative Interstitial Pneumonia (DSIP)
What is the treatment for DSIP?
- stop smoking!
- corticosteriods
- good prognosis: >95% survival at 5 years
Within the spectrum of DSIP, but less symptomatic and earlier presentation (30-40 years old)
- smoking-related (dose dependent)
Respiratory Bronchiolitis-Interstitial Lung Disease (RB-ILD)
NOTE: often reversible with smoking cessation if caught early
What is required to diagnose RB-ILD?
radiographic abnormalities on chest CT prompt biopsy
What is seen histologically in RB-ILD?
- macrophages present to a lesser extent
- “peribronchiolar” metaplasia
- may have fibrosis in advanced cases
Young smoker, presents with stellate lung lesion
Langerhands Cell Histiocytosis (LCH)
What is seen histologically in LCH?
- eosinophils
- langerhands cells (immature dendritic cells)
- varying fibrosis and cysts
Why would a patient with LCH present with pneumothorax?
- progressive scarring leads to cysts
2. peripheral cysts may rupture!!
Can LCH be reversed with smoking cessation?
yes!
What lab values are considered a giveaway for LCH?
CD1a positive, and abundant eosinophils
Impairment of surfactant metabolism due to defect of granulocyte-macrophage color stimulating factor (GM-CSF)
- accumulation of surfactant proteins throughout alveoli and airspaces
Pulmonary alveolar proteinosis
What are the typical demographics of pulmonary alveolar proteinosis patient?
- autoimmune pt (middle-aged female most likely)
- fluid collected from bronchioalveolar lavage shows copious amount of milky fluid
How can you treat pulmonary alveolar proteinosis?
GM-CSF (subcutaneous)
What do pulmonary infarcts look like?
wedge-shaped lesions
- begin as hemorrhagic, then fibrosis sets in
What is a saddle pulmonary embolism?
an emboli that wedges in primary arterial trunk
- patient dies of acute cor pulmonale because right heart can pump against pressure buildup
- they die before infarction/necrosis sets in
What is a hallmark of antemortem (before death) clots?
Lines of Zahn
What can obstruct vessels in a pulmonary emboli?
- blood clot
- bone marrow/fat
- cancer (tumor embolus)
- septic emboli
- air
- foreign material
- parasites (dorofilaria)
When would you see a bone marrow embolism?
after trauma
What is a talc embolism (looks shiney on gross biopsy) characteristic of?
IV drug users
What can cause nodules in drug users?
**septic emboli **
What is a septic emboli?
bloodborne infective material, valve vegetations break off and manifest in other sites -> LUNGS!
When might you see a septic emboli?
endocarditis
NOTE: look for Janeway lesions on skin, Roth spots in retina, and splinter hemorrhages in nailbed
What is the definition of pulmonary HTN?
pulmonary artery pressure (PAP) greater than 25 mmHg
What are the subgroups of pulmonary HTN?
- pulmonary arterial HTN (PAH)
- secondary to left heart failure
- secondary to chronic pulmonary parenchymal disease
- secondary to thromboembolic pulmonary disease
- multifactorial
What histological finding is very characteristic of pulmonary HTN?
plexiform lesion
What is medial hypertrophy?
when there is smooth muscle in small arteries
- is a good indicator of pulmonary HTN
What do Goodpasture syndrome, granulomatosis with polyangiitis, and idiopathic pulmonary hemosiderosis have in common?
they are all pulmonary hemorrhage syndromes
What is a hallmark of pulmonary hemorrhage syndrome on a histo slide?
** hemosiderin-laden macrophages **
What are immunofluorescence showing a LINEAR pattern of deposition due to anti-basement membrane antibodies characteristic of?
Goodpasture syndrome
- can see RBC in lungs (not good!)
What does Goodpasture syndrome result from?
antibody-mediated damage to basement membranes in the lung and kidney
- Ab against collagen :(
What type of hypersensitivity reaction is Goodpasture syndrome?
type 2
What does granulomatosis with polyangiitis remind you of on a histo slide?
Tb (or other serious infection)
What is the most common cause of sepsis and septic shock?
pneumonia
What are the two categories of pneumonia?
- clinical setting
2. anatomic distribution
What are the two types of “anatomic distribution” pneumonia?
- bronchopneumonia
2. lobar pneumonia
What are the 4 stages of lobar pneumonia?
- congestion (vascular engorgement)
- red hepatization (red cells + inflamm)
- grey hepatization (inflamm + debris)
- resolution (fibrosis, macrophage clean-up)
What is considered a system-specific process of acute inflammation?
lobar pneumonia
What are the complications of lobar pneumonia?
solidification in the lung due to intense inflammatory process
- abscess
- empyema (puss-filled)
- bacteremia can spread! very dangerous!
What organisms can lead to community-acquired bacterial pneumonia (CAP)?
- S. pneumoniae
- H. influenzae
- S. aureus
- K. pneumoniae
- P. aeruginosa
- L. pneumophilia
- M. pneumoniae
What is the most common cause of CAP?
S. pneumoniae
- lancet-shaped gram positive diplococci (pairs and chains)
What population is vaccination for S. pneumoniae recommended for?
infants, patients older than 65 years, and respiratory disease/smoking population
What organism causes virulent pneumonia in children?
H. influenzae
- recommended vaccination for type B for children younger than 5 years
What organism causes abscess formation
S. aureus
- seen in IV drug users
What organism causes currant jelly sputum
Klebsiella pneumoniae (gram negative) - seen in alcoholics
What population would you see Pseudomonas aeruginosa infection?
cystic fibrosis
NOTE: aeruginosa = copper rust
Which type of pneumonia presents as:
- abrupt onset
- predominant respiratory symptoms
- consolidation on CXR
- older adults or young children
Typical pneumonia
Which type of pneumonia presents as:
- slower onset
- systemic symptoms
- patchy infiltrates on CXR
- young adults/teens/older children
“Atypical/walking” pneumonia
What do “patchy infiltrates” look like on CXR?
very fine white lines
What does typical pneumonia look like on CXR?
very dark/consolidated areas
What organisms cause typical pneumonia?
- S. pneumoniae
- H. influenzae
- S. aureus
- K. pneumoniae
- P. aeruginosa
What organisms cause “atypical” pneumonia?
- Mycoplasma pneumoniae has no cell wall!
- Legionella pneumophila
- chlamydia pneumonia
- chlamydia psittaci
What is the smallest free-living, self-replicating microorganism that lacks a cell wall?
Mycoplasma pneumoniae
- is tiny! smaller than cilia, so can progress very far down respiratory tract
Gram negative bacillus, grows in warm freshwater (AC units/misters/hot tubs)
- airborne disease (not person-person spread)
Legionella pneumophila
Influenza, SARS and RSV are examples of what?
community-acquired viral pneumonia
What are the 2 proteins that classify influenza virus?
- hemagglutinin (attaches to cells)
2. neuraminidase (allows release of replicated virus from cells)
What is the MOA of neuraminidase?
it is a viral enzyme that cleaves the hemagglutinin tether anchoring the viron to the infected body cell
- once the tether is cleaved, the virion is released to infect other body cells
What does Tamiflu do?
it inhibits neuraminidase, so virion particles get stuck, and cannot infect other cells
Describe antigenic DRIFT
- epidemic
- minor changes to proteins (antigens) on the virus, allow increased speed
- similar enough to original virus to allow for some immunity
Describe antigenic SHIFT
- pandemic
- genomic alterations with major resulting changes to protein structure
- naive immunity for almost all people
- picked up from animal gene products
What was so bad about H1N1 virus?
it was a recombination of bird and swine virus
- spread so fast because we had no immunity to its recombination
What disease is caused by coronavirus, originating in China, with a worldwide outbreak from 2002-2004?
Severe Acute Respiratory Syndrome (SARS)
What is the most likely cause of pneumonia in neonates/
bacterial: Group B strep, gram negative bacilli, Listeria
What is the most likely VIRAL cause of pneumonia in children older than 1 month?
- respiratory syncytial virus
- parainfluenza virus, influenza A/B adenovirus, rhinovirus
What is the most likely BACTERIAL cause of pneumonia in children older than 1 month?
S. pneumoniae, H. influenzae, M. catarrhalis, S. aureus
What are additional bacterial considerations for pneumonia in older children/adolescents?
M. pneumoniae, C. pneumoniae
Patient presents with symptoms of rhinorrhea, cough
- wheezing** and dyspnea
- tachypnea
- cyanosis
Respiratory Syncytial virus (RSV)
- virus replication results in epithelial-cell sloughing, inflammatory cell infiltration, edema, increased mucus secretion, and impaired ciliary action
What is the general presentation of bacterial pneumonia?
- abrupt onset
- not associated with epidemics
- may have associated bacteremia
- high grade fever
- crackles on lung exam
- lobar or consolidated appearance
- may involve pleura
- responds quickly to appropriate antibiotics
What is the general presentation of viral pneumonia?
- gradual onset
- epidemics are common
- not typically associated with viremia
- no fever/low grade fever
- wheezes on lung exam
- diffuse infiltrates on CXR
- doesn’t typically involve pleura
- will not respond to antibiotics
Lung abscesses are complications of pneumonia caused by which two organisms?
- S. aureus
- Klebsiella pneumoniae
When are you likely to see a lung abscess due to aspiration?
- chronic alcoholics
- elderly patients, stroke
- anaerobic bacteria
What is aspiration pneumonia?
- abscess formation in acute bacterial pneumonia
- food particle in inflammatory exudate indicating aspiration
- large neutrophilic exudate causing inflammation
When are you most likely to see a caseating granulomata?
Tb
What is a Ghon complex?
area of hyaline/consolidated necrosis with a distinct border, giant cells on the outside of the border
What is chronic pneumonia?
pneumonic process lasting for months in an immunocompetent patient
What 3 fungi can cause chronic pneumonia?
- Histoplasma
- Blastomycosis
- Coccidiomycosis
Which fungi:
- is endemic in midwest and Carribean (Ohio/Mississippi river valleys)
- typically presents as subclinical infection with granulomatous response (calcifications/coin lesions on CXR)
- characteristic yeast form shows pumpkin seed morphology
- runs aggressive course, especially in immunocompromised patients
Histoplasma capsulatum
Which fungi:
- is endemic in central and SE US (Ohio/MI river valleys)
- in the lungs, infection yields granulomatous response
- characteristic yeast forms show broad-based budding
- also infects skin and rarely, spreading infection
Blastomyces dermatitides
Which fungi:
- is endemic in SW US and Mexico
- in the lungs, infection yield a granulomatous response with eosinophils
- often a subclinical, self-limited disease
- can produce spreading infection, especially in immunocompromised patients
Coccidiodes immitis
Histo slides will show large sphere filled with endospores*
Which fungi:
- is opportunistic
- causes an AIDS-defining illness
- has characteristic cup-shaped yeast forms
- can be diffuse or focal cysts on radiograph
Pneumocystic jiroveci (carinii)
Immunocomprimised (or elderly) patient presents with thin mycobacteria seen on slender red forms on acid-fast stainging
Mycobacterium avium complex (MAC)
Post lung transplantation, why are regular biopsies necessary?
they are needed to discriminate infection from rejection (which can also produce infiltrates and fever)
NOTE: rejection shows mononuclear infiltrates around vessels
