Abnormal pulmonary interstitial morphology Bronchiolitis obliterans organizing pneumonia 2012-06-18T07:55:41Z Cryptogenic organizing pneumonia UMLS:C0242770 Cryptogenic organising pneumonia SNOMEDCT_US:129458007 HP:0011945 BOOP Bronchiolitis obliterans organising pneumonia Bronchiolitis obliterans organizing pneumonia (BOOP) is and interstitial lung abnormalitiy characterized histopathologically by plugs of granulation tissue lying within small airways, alveolar ducts, and alveoli and by chronic inflammatory cell infiltration in alveolar walls. Patients with BOOP generally present with subacute illness, including shortness of breath, fever, malaise, and weight loss.