Bilateral ground glass and consolidation with centrilobular nodules and, days later, crazy paving — with haemoptysis, a falling haemoglobin and a vasculitis or anticoagulation context; BAL with sequentially bloodier returns confirms it.
Orient first
- Causes: ANCA vasculitis, anti-GBM disease, SLE, anticoagulation, drugs, bone marrow transplant.
- Haemoptysis is absent in a third; the imaging and a haemoglobin drop may be the first clue.
- Clearing within days separates it from infection and oedema.
Acquire the study
- Non-contrast CT chest with thin sections.
The manoeuvre
- Axial lung window: bilateral ground glass and consolidation — distribution usually central and perihilar, sparing the periphery.
- Centrilobular ground-glass nodules.
- Crazy paving (septal thickening over ground glass) after 2–3 days.
- Effusions and nodes minimal; compare with prior study for rapid change.
- Kidneys or sinuses if imaged (pulmonary-renal syndromes).
What confirms it
- Progressively haemorrhagic BAL returns with haemosiderin-laden macrophages and a compatible CT.
What licenses you to exclude it
- CT cannot exclude small-volume haemorrhage; BAL can.
The classic misread
- Calling it pneumonia and missing the vasculitis.
- Calling crazy paving alveolar proteinosis without the clinical context.