Lec 9 Pneumonia Pathology Flashcards
Bronchopneumonia: what do you see in image
image: patchy consolidation of lung centered on bronchi
Lobar pneumonia: what distinguishes it?
- affects entire lung lobe
- associated with increased virulence of organism or most host vulnerability [infants, elderly]
What do you see on histology with bacterial pneumonia?
neutrophils in bronchi, bronchioles, and adjacent alveolar spaces
Can you tell which bacteria just from histology image?
Not reallly
staph aureus = really virulent so more likely to cause hemorrhage
pseudomonas = likes to hang out around RBCs + invade blood vessel wall
What puts you at risk for community acquired pneumonia?
usually baceteria or virus
- Extremes of age
- Chronic diseases (congestive heart failure, COPD, and diabetes)
- Congenital or acquired immune deficiencies
- Decreased or absent splenic function (sickle cell disease or post splenectomy
WHat is major cause of community acquired pneumonia?
strep pneumo = 80-90%
Who is at risk for nosocomial pneumonia?
- pt with severe underlying disease
on mechanical ventilater
What bugs cause nosocomial pneumonia?
staph aureus
pseudomonas
other gram neg rods [klebsiella, legionella]
EColi
What bugs cause community acquired pneumonia?
- stre pneumo
- H influenza
- klebsiella, legionella
- staph aureus
What are potential outcomes of bacterial pneumonia?
- resolution
- pleural effusion
- empyema
- fibrosis
- abcess
- bacteremia
What is a lung abscess? what causes it?
localized collection of pus within parenchyma
cause: 2ndary to bacterial or fungal infection; bronchila obstruction; septic emboli; aspiration
What are symptoms of lung abscess
cough, fever, foul-smelling sputum, fever, chest pain, weight loss
What is treatment of lung abscess?
need to resect
What is atypical pneumonia? most common causes?
pneumonia without alveolar exudate
largely confined to alveolar septa and pulmonary interstitium
lymphocytic infiltrate in interstitium rather than neutrophils in air spaces [as in typical]
see patchy inflammatory changes in lungs
most commonly due to mycoplasma, viruses
What is morphology of atypical pneumonia?
- predominant in interstitium
- localized within walls of alveoli
- widened septa filled with inflammatory infiltrate of lymphocytes and occassionally plasma cells
intra-alveolar neutrophils generally absent
What type of viral infections involve lung?
- cytomegalovirus
- herpesvirus
- adenovirus
- influenza
What pts generally get viral pneumonia?
pts who are immune compromised by
- AIDS
- chemo
- transplant
what does CMV infection look like
intranuclear and intracytoplasmic inclusions
big cell [meGALO] with huge dark nucleus from intranuclear inclusion
KNOW THIS
What does herpes infection look like?
ulcerative process involving airways
multi-nucleated big cells with intranuclear inclusions [not intracellular]
nuclei tend to mold together = pomegranite appearance
KNOW THIS
What does adenovirus infection look like?
single large intranuclear inclusion = “smudge cell”
tend not to form big pneumocytes like the others
no intracytoplasmic inclusions
What does primary TB infection look like?
caseating/necrotizing granuloma
What is ghon complex?
primary pulm granuloma [usually above or below interlobar fissure PLUS involvement of hilar lymph nodes
Where does secondary TB usually involve?
lung apex
How does miliary TB look?
multiple small granulomas in lungs
can spread to other organs due to lymphatic and hematogenous spread
