2.1.3 Infectious Disease of the Lung

Question 1

How could you distinguish between lobar pneumonia and bronchopneumonia on a histologic slide?

Answer 1

If the bronchi were filled with pus, it would be called bronchopneumonia. If it is in the alveoli, it is lobar pneumonia, by definition.

Question 2

What is the most common organism to cause pneumonia?

Answer 2

Streptococcus pneumoniae

Question 3

What is this an image of?

Answer 3

Lobar pneumonia

Question 4

What are complications associated with TB?

Answer 4

Question 5

Who is at risk for Pneumocystis jirovecii infection?

Answer 5

HIV patients with <200 CD4 count

Question 6

What is this an image of?

Answer 6

Pneumocystis jirovecii

Also know that a BAL can be a good diagnostic test for this

Question 7

What is this an image of?

Answer 7

Lung that has a hole in it after infection and liquefactive necrosis.

Question 8

How would lobar pneumonia show up on a CXR?

Answer 8

It would show up as a tissue density on a chest X-Ray.

Question 9

Why is it important to get a patient with pneumonia on antibiotics as soon as possible?

Answer 9

To prevent scarring of the lung tissue

Question 10

What are some of the complications of pneumonia?

Answer 10

Question 11

What are the different clinical classifications of aspergillosis? *Important

Answer 11

Question 12

What are the stages of lobar pneumonia?

Answer 12

Question 13

What is the most frequent cause of gram-negative bacterial pneumonia?

Answer 13

Klebsiella pneumoniae

Question 14

What is this an image of?

Answer 14

Pneumocystis jirovecii - silver stain

Question 15

What is this an image of? (Hint: Lab studies make this disease worse than the patient is presenting)

Answer 15

Legionella CXR - affecting the RUL

Question 16

Walking pneumonia

Patient seems pretty fine

What bacteria are these characteristics of?

Answer 16

Mycoplasma pneumoniae

Question 17

What is this an image of?

Answer 17

Lobar pneumonia - notice how nearly every alveoli is filled with pus.

Question 18

What is this an image of?

Answer 18

This is a CXR of a lobar pneumonia

Question 19

What is this an image of?*

Answer 19

Aspergillosis (Blood vessel invasion/thrombosis)

Aspergillus will invade blood vessels, and cause thrombosis and infarction, and those infarcts can occur anywhere in the body, not just the lung

Question 20

What is the most common way that organisms are introduced to the lower respiratory tract?

Answer 20

Aspiration of flora from the oropharynx

Question 21

What are the important characteristics of legionella pneumophilia?

Answer 21

It is an intracellular organism, requiring antimicrobial drugs with good cytoplasmic penetration. Biochemical abnormalities may seem more severe than patient presents. Requires special media to grow

Question 22

What is this an image of?

Answer 22

Klebsiella pneumoniae

Notice the abcess formation

Question 23

Patient has a Staphylococcus aureus infection, and presents with this CXR. What is a common cause that he got it?

Answer 23

This is bilateral Staph pneumonia. It is most likely cause by IV drug abuse

Question 24

What is this an image of?

Answer 24

Interstitial pneumonia - CT Scan

Question 25

What are the characteristics of community-acquired pneumonia?

Answer 25

Community-acquired acute pneumonia refers to lung infection in otherwise healthy individuals that is acquired from the normal environment (in contrast to hospital acquired pneumonia). It may be bacterial or viral. Rarely seen either resolves or **progresses to cause lobar pneumonia** Neutrophilic reaction and **abundant sputum** RLL is the most common area affected

Question 26

Gram stain positive Most common source of community acquired pneumonia What are these characteristic of?

Answer 26

Strep pneumo

Question 27

What is this an image of and what caused it? \*Very important

Answer 27

Invasive Aspergillosis that caused a lung infarct -

Question 28

What population does Klebsiella pneumoniae most often afflict?

Answer 28

Debilitated and malnourished people, **particularily alcoholics**

Question 29

What is this an image of?

Answer 29

CXR of TB - Miliary TB

Question 30

Bacteria most associated with lung necrosis and abcess formation Drug users

Answer 30

Staph aureus

Question 31

What are the clinical features of Haemophilus influenzae?

Answer 31

Gram-negative Mainly a problem with children Common cause of COPD exacerbation

Question 32

What is this an image of?

Answer 32

Legionella - IF sputum staining

Question 33

What is this an image of and what is the stain?

Answer 33

Legionella - Dieterle stain

Question 34

What are the types of pneumonia?

Answer 34

Community-Acquired pneumonia Atypical pneumonia Bronchial pneumonia Lobar pneumonia

Question 35

What can be used to make a diagnosis of pneumonia?

Answer 35

Most Important - Presentation of clinical symptoms and/or the presence of infiltrate on CXR or CT Scan. Blood cultures are also helpful Less important - sputum culture

Question 36

What are these images of?

Answer 36

Hemorrhagic Tracheobronchitis - Influenza A

Question 37

What is the most likely population to aspirate?

Answer 37

Institutionalized (nursing home patients) patients are more likely to aspirate They also have an altered oral flora, which can include many gram negative and anaerobic organisms

Question 38

What are the characteristics of atypical pneumonia?

Answer 38

Low grade fever, patchy consolidation and has a non-productive cough

Question 39

What is this an image of?\*

Answer 39

Aspergillus niger

Question 40

What is this an image of?

Answer 40

S. pneumoniae - sputum gram stain

Question 41

What is circled in this image?\*

Answer 41

Aspergilloma - There is no invasion of tissue by the fungus. It respects the boundaries of the previously existing abscess cavity.

Question 42

What is this an image of?

Answer 42

This is an aspergilloma - it exists within a previously existing space, most likely an old abcess

Question 43

What is the difference between these two images?

Answer 43

Left - bronchopneumonia Right - Lobar pneumonia

Question 44

In a patient with pneumocystis jirovecii infection and a normal immune system, how will the infection present?

Answer 44

It will tend to be asymptomatic in a patient with normal immune system

Question 45

What is this an image of?

Answer 45

TB - gross finding Notice - Caseous necrosis and cavitation in advanced TB

Question 46

What is the difference between primary TB and secondary TB?

Answer 46

Question 47

What is this an image of?

Answer 47

Cytomegalovirus - Owl eye inclusion in the nucleus. Immunocompromised host

Question 48

What is the difference between these two images?

Answer 48

Left - Normal ciliated columnar epithelium Right - rhinovirus infected epithelium