Chronic Granulomatous Disease

Chronic granulomatous disease is a rare congenital immunodeficiency caused by a genetic defect that prevents phagocytic cells from killing catalase positive organisms such as Staphylococcus aureus, Burkholderia cepacia, and Aspergillus. These organisms are phagocytized, but not killed, leading to a chronic inflammatory response and granuloma formation.

Most patients present in their first few years of life with nonspecific findings. Imaging studies may reveal the pattern of infection, inflammation, and granuloma formation.

Chronic granulomatous disease is characterized by recurrent bacterial and fungal infections with granuloma formation. While the lungs are most commonly, involved, lymphatic, hepatic, skeletal, gastrointestinal, genitourinary, head and neck, and the central nervous system can also be affected.

In the lungs, pneumonia is the most common presentation, with Aspergillus being the most common organism isolated (40%), followed by Staphylococcus (10%), Burkholderia cepacia (5%), and Nocardia (5%). Imaging findings are as would be expected for the various bacterial and fungal infections. Complications of recurrent infections include pulmonary fibrosis with honeycombing, pulmonary artery hypertension, and pleural thickening.

Lymphadenopathy and suppurative adenitis are common. Mediastinal or hilar adenopathy are the most common findings, followed by cervical adenopathy (as seen in the image above). suppurative adenitis presents as enlarged, enhancing lymph nodes with a central area of low attenuation. Thick, enhancing septations may be present. Granuloma formation can also occur in lymph nodes. Granuloma formation in nodes or sequelae of suppurative infection may lead to calcified lymph nodes (as seen in hilar nodes above).

Multiple other organs can be involved:

• Ear, nose, and throat: Sinusitis seen in 15%, with fungal infections more common than in the general population.
• Brain: Encephalitis, brain abscesses, meningitis (Candida most common), and granulomatosis uncommon.
• Bone: Most commonly Serratia marcescens followed by Aspergillus
• Upper gastrointestinal tract: Dysmotility and strictures.
• Lower gastrointestinal tract: Can mimic Crohn disease with skip lesions, wall thickening, luminal narrowing, fistulation, and a cobblestone mucosal pattern
• Liver: Abscesses and granulomas. Hepatosplenomegaly can also be seen.
• Spleen: Abscesses and granulomas. Hepatosplenomegaly can also be seen.
• Lower genitourinary tract: Inflammatory pseudotumors of the bladder.
• Kidneys: Pyelonephritis and renal abscesses uncommon.

References

Towbin AJ, Chaves I. Chronic granulomatous disease. Pediatr Radiol. 2010 May;40(5):657-68.