Chronic granulomatous disease
CGD is an inherited phagocyte dysfunction (NADPH oxidase oxidative burst failure) causing recurrent deep infections and granulomatous inflammation. Imaging clue: multi-site, recurrent abscesses and pneumonias, often with fungal-pattern lung disease and liver abscesses, in a young patient (classically male).
Pathophysiology
- Poor intracellular killing by neutrophils/macrophages → persistent infection
- Chronic inflammation → granulomas that can behave like obstructing masses
Imaging patterns
Chest (most common)
Think CGD when CT shows recurrent multifocal infection with nodules, cavitation, and abscess, especially if fungal infection is suspected.
- Recurrent pneumonia: patchy or lobar consolidation, often multi-lobar over time
- Multiple nodules (can wax/wane); may cavitate
- Lung abscess or necrotising pneumonia
- Fungal disease (classically Aspergillus): nodules ± surrounding ground-glass, cavitation, pleural-based lesions
- Complications: bronchiectasis can develop after repeated infections
Lymph nodes
- Suppurative lymphadenitis: enlarged nodes with central low attenuation and rim enhancement
- Mediastinal nodes can mimic TB/lymphoma depending on context
Liver and spleen
Multiple hepatic abscesses in a child or young adult with recurrent infections is a strong CGD-shaped clue.
- Multiple hepatic abscesses; sometimes “cold” clinically relative to imaging
- Splenic microabscesses or larger splenic abscesses
- US for detection, CT/MRI for extent, complications, and drain planning
Gastrointestinal tract
- Granulomatous colitis that can mimic Crohn disease
- Imaging: bowel wall thickening, hyperenhancement, strictures; perianal disease can occur
- Pitfall: calling it Crohn without integrating infection history
Genitourinary obstruction
- Granulomas can cause focal inflammatory masses leading to obstruction
- Hydronephrosis or bladder outlet symptoms with atypical infection history should prompt immune defect consideration
Bones and soft tissues
- Chronic osteomyelitis (including unusual organisms)
- Deep soft-tissue abscesses (psoas, abdominal wall, perineal), recurrent or multifocal
Microbiology clue words
Catalase-positive organisms: Staphylococcus aureus, Serratia, Burkholderia cepacia complex, Nocardia; plus Aspergillus (big one).
Differential
- TB or atypical mycobacterial infection (nodes, lung)
- Lymphoma (nodes, systemic)
- Sarcoidosis (granulomas without suppuration)
- Crohn disease (GI)
- Other immunodeficiencies or iatrogenic immunosuppression
Imaging cannot diagnose CGD. The radiology value is pattern recognition and prompting immune evaluation early, especially when disease recurs, is multi-site, or looks fungal/atypical.
