Pulmonary Alveolar Proteinosis

Question 1

What is Pulmonary Alveolar Proteinosis (PAP)?

Answer 1

Pathophysio:
1. Unknown cause
2. Filling of alveolar space with PAS-positive lipoproteinaceous material
3. Due to excessive secretion and disrupted clearance of surfactant by alveolar macrophages

Question 2

What are the PAP CT findings and the DDx?

Answer 2

CT findings:
Patchy,
Well demarcated crazy-paving pattern
Geographic pattern

DDx:
PCP,
CMV,
bronchioloalveolar cell carcinoma (BAC)

Question 3

How to treat PAP?

Answer 3

BAL

Question 4

What are the complications of PAP?

Answer 4

Secondary infection:
TB,
NTM,
nocardia
cryptococcus infection