Medical mucoid lesions of the pulmonary artery in cystic fibrosis, pulmonary hypertension, and other disorders.

Alterations in the pulmonary vascular bed were reviewed in the autopsy material 
from 35 patients with cystic fibrosis of the pancreas and cor 
pulmonale. Hypertrophy of the media or intimal proliferation of small muscular 
arteries and arterioles was noted in eight patients; intimal proliferation of 
the larger caliber arteries was seen in seven patients. The unexpected 
change, however, was the presence of interstitial hyaline material in the 
media of the pulmonary artery or its major branches in one-third 
of the specimens. The elastic fibers were distorted, but not disrupted, 
and the finding was unrelated to the presence or severity of 
other vascular changes. Intimal deposits of the same material were also 
present in seven of the patients with intimal proliferation in major 
pulmonary arteries. Identical medial lesions were found in the pulmonary arteries 
of seven of 35 children with pulmonary hypertension and in seven 
patients with other disorders. Similar lesions in the media of the 
aorta were found in each group of patients. The material was 
not Schiff-reactive, but had the histochemical characteristics of a connective tissue 
acid mucopolysaccharide. 