Alveolar opportunistic pneumonia pattern vs Angioinvasive mold pneumonia pattern
How to tell Alveolar opportunistic pneumonia pattern and Angioinvasive mold pneumonia pattern apart when a board question makes them look alike.
Alveolar PCP pattern is diffuse dry hypoxemic ground-glass disease; angioinvasive Aspergillus pattern is nodular/cavitary with halo, infarction, or hemoptysis.
Side by side
Alveolar opportunistic pneumonia, classically PCP, causes subacute dry cough, dyspnea, hypoxemia, diffuse bilateral ground-glass/interstitial infiltrates, elevated LDH, and risk at CD4 below 200 or immunosuppression.
Angioinvasive mold pneumonia, classically Aspergillus, occurs in neutropenia, transplant, chronic steroids, or lung cavities with nodules, halo sign, cavitation, hemoptysis, pleuritic pain, or fungus ball.
Pneumocystis jirovecii causes alveolar infection with impaired gas exchange rather than angioinvasive hyphal disease.
Aspergillus forms septate acute-angle branching hyphae that can invade vessels and infarct lung tissue.
Beta-D-glucan, BAL/sputum staining or PCR, diffuse ground glass, and severe A-a gradient support PCP.
Galactomannan, fungal culture/histology, septate acute-angle hyphae, halo sign, and neutropenia support invasive aspergillosis.
The trap
Both occur in immunocompromised hosts, but CD4-related diffuse hypoxemia points to PCP while neutropenic nodules/halo/hemoptysis point to Aspergillus.
The repair move
For immunocompromised pneumonia, separate alveolar gas-exchange disease from angioinvasive nodular mold disease.
Try a free question
CoreA patient with AIDS and CD4 count 120 has dry cough, progressive dyspnea, hypoxemia, elevated LDH, and diffuse bilateral ground-glass infiltrates. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Pneumocystis pneumonia. CD4 below 200 with subacute dry hypoxemic diffuse ground-glass pneumonia supports PCP.
Why the other choices are tempting
- B. Aspergillus pneumonia is more nodular/cavitary and angioinvasive, often in neutropenia/transplant.
- C. Mucormycosis causes broad right-angle hyphal angioinvasion.
- D. Coccidioidomycosis is endemic Southwest spherule disease.
- E. Cellulitis is skin/subcutaneous infection.
Flashcards
Tap a card to flip it.
What CD4 threshold supports PCP?
CD4 below 200 supports Pneumocystis pneumonia.
What imaging pattern supports PCP?
Diffuse bilateral ground-glass or interstitial infiltrates support PCP.
Quick answers
What is the fastest way to tell Alveolar opportunistic pneumonia pattern from Angioinvasive mold pneumonia pattern?
Alveolar PCP pattern is diffuse dry hypoxemic ground-glass disease; angioinvasive Aspergillus pattern is nodular/cavitary with halo, infarction, or hemoptysis.
What is the key clue for Alveolar opportunistic pneumonia pattern?
Alveolar opportunistic pneumonia, classically PCP, causes subacute dry cough, dyspnea, hypoxemia, diffuse bilateral ground-glass/interstitial infiltrates, elevated LDH, and risk at CD4 below 200 or immunosuppression.
What is the key clue for Angioinvasive mold pneumonia pattern?
Angioinvasive mold pneumonia, classically Aspergillus, occurs in neutropenia, transplant, chronic steroids, or lung cavities with nodules, halo sign, cavitation, hemoptysis, pleuritic pain, or fungus ball.
What is the common trap with Alveolar opportunistic pneumonia pattern vs Angioinvasive mold pneumonia pattern?
Both occur in immunocompromised hosts, but CD4-related diffuse hypoxemia points to PCP while neutropenic nodules/halo/hemoptysis point to Aspergillus.