Pediatric Lymphoid Interstitial Pneumonia

Etiology: Benign lymphoproliferative disorder caused by human immunodeficiency virus or Ebstein Barr virus
Imaging CXR:
— Nonspecific
— Diffuse, symmetrical, reticulonodular or nodular infiltrate with or without hilar and mediastinal adenopathy
— Nodules are 2-3 millimeters in size at bases and periphery
Imaging CT:
— Mid to lower lobe thickening of bronchovascular bundles along lymphatic channels
— Small but variable sized pulmonary nodules
— Mediastinal lymphadenopathy
DDX:
Complications:
— May resolve or may progress to end stage interstitial lung disease
— May rarely progress to lymphoma
Treatment: Steroid responsive
Clinical:
— 30-40% of perinatally infected HIV babies get lymphocytic interstitial pneumonitis
— Presents with gradual onset of dyspnea and cough over several months

Radiology Cases of Lymphoid Interstitial Pneumonia

CXR of lymphoid interstitial pneumonia — Initial CXR AP and lateral (above) show diffuse reticular interstitial infiltrates throughout the lungs bilaterally. CXR AP several months later (below) shows some interval clearing of the reticular infiltrates.

CXR of lymphocytic interstitial pneumonitis / LIP — CXR AP shows bilaterally diffuse, symmetrical, nodular infiltrates.

CXR of lymphoid interstitial pneumonia — CXR AP and lateral (above) show a diffuse, symmetrical, nodular infiltrate in the lungs bilaterally without hilar or mediastinal adenopathy. CXR AP obtained a year later (below) shows the nodular infiltrate has decreased slightly in the interval.

CXR of lymphoid interstitial pneumonia — CXR AP and lateral (above) shows a diffuse, symmetrical, reticulonodular infiltrate which is better appreciated on the magnified view (below). There is no hilar lymphadenopathy.