What are the pulmonary and extrapulmonary manifestations of cystic fibrosis?
Cystic fibrosis is an autosomal recessive disorder of abnormal chloride ion transport, which results in backup of thick mucus secretions in various organs. In the lungs, cystic fibrosis manifests as repeated infections that result in bronchiectasis, predominantly in the upper lobes. On chest radiographs, bronchiectasis may appear as multiple lucent holes or tram-track opacities, which may be fluid filled. Areas of atelectasis or lung hyperaeration may also be seen. On CT, bronchiectasis is generally present when bronchi are larger in diameter than the adjacent pulmonary arteries or extend to within 1 cm of the pleural surface. Some extrapulmonary manifestations include neonatal meconium ileus (small bowel obstruction at the terminal ileum from inspissated meconium), chronic pancreatitis, and cirrhosis. An enlarged spleen may result from portal hypertension and may manifest on a chest radiograph with medial deviation of the stomach bubble in the left upper quadrant.