Learning objectives
Illustrating the clinical and radiological features of Cryptogenetic Organizing Pneumonia (COP),
highlighting the radiological patterns andfindings that may facilitate radiologists in the differential diagnosis.
Background
Organizing pneumonia is a clinical,
radiological and histological pattern characterized by the presence of granulation tissue within the terminal or respiratory bronchioles,
in the alveolar ducts and surrounding alveoli (note that the bronchiolar component may be lacking) and chronic inflammation of the remaining lung parenchyma [1].
OP can be secondary to many extra-lung conditions (infections [2],
drug toxicity [3-6],
radiotherapy [4,7,8],
collagen diseases [9],
oncologic conditions [10,11] or pulmonary conditions ( pneumonia,
vasculitis,
lung cancer)or it can be cryptogenic [2].
The idiopathic form of OP...
Findings and procedure details
Radiologic features
The patterns of COP can be divided into two main groups: typical and atypical [23].
The main HRCT findings in OP include: consolidation,
ground-glass opacification,
peri-lobular opacity,
reversed halo opacity,
nodule or mass,
parenchymal bands,
bronchial wall thickening,
bronchial dilatation,
mediastinal lymphadenopathy and pleural effusion [24].
Typical COP consist of multiple alveolar opacities; atypical pattern includes: nodular pattern (solitary or multiple nodules or masses),
infiltrative opacities (infiltrative COP),
atoll sign,
broncho-centric lesions,
linear and band-like opacities,
crazy paving pattern and progressive fibrosis [14,21,23,25]....
Conclusion
COP can present itself in a large range of ways,
and may mimic various HRCT patterns.
Therefore,
it is necessary to recognize their clinical features and their different radiological presentation patterns,
in order to exclude all differential diagnoses patterns.
References
[1] Epler GR,
Colby T V,
McLoud TC,
Carrington CB,
Gaensler EA.
Bronchiolitis Obliterans Organizing Pneumonia.
N Engl J Med 1985;312:152–8.
doi:10.1056/NEJM198501173120304.
[2] Cordier J-F.
Organising pneumonia.
Thorax 2000;55:318 LP-328.
[3] Fekrazad MH,
Eberhardt S,
Jones D V,
Lee F-C.
Development of bronchiolitis obliterans organizing pneumonia with platinum-based chemotherapy for metastatic rectal cancer.
Clin Colorectal Cancer 2010;9:177–8.
doi:10.3816/CCC.2010.n.024.
[4] Masetti R,
Cazzato S,
Prete A,
Rondelli R,
Di Vincenzo AO,
Pession A.
Organizing pneumonia primed by high-dose chemotherapy and lung irradiation: two pediatric cases.
J...