Figures
- FIGURE 1
Histopathology of organising pneumonia. a) Typical Masson body (intraluminal plug of mucopolysaccharide-rich fibroblast proliferation without evidence of collagenous fibrosis). b) Masson body that is beginning to fibrose. Note pink strands of collagen starting to accumulate within the Masson body. c) Two Masson bodies that have undergone complete collagenous fibrosis and appear somewhat shrunken within the alveolar spaces. Photomicrographs provided courtesy of Scott Aesif (Dept of Pathology, Cleveland Clinic, Cleveland, OH, USA).
- FIGURE 2
High-resolution computed tomographic imaging of organising pneumonia. a) Multiple areas of bilateral subpleural consolidation. b) Resolving lesions following 4 weeks of treatment with prednisone. c) Nodular consolidation with air-bronchogram. d) Ground-glass opacification. e and f) Multiple bilateral areas of nodular consolidation in a 58-year-old female (lung biopsy showed histopathologic changes of organising pneumonia. g) Near resolution following 2 months of corticosteroid therapy. h) Relapse with new lesions at 4 months following initial diagnosis despite treatment with 40 mg of prednisone daily. The patient eventually improved with mycophenolate plus azithromycin and was gradually tapered off all drugs over 6 months following her second relapse (no recurrence was noted over 5 years of follow-up after all therapy was discontinued).
- FIGURE 3
Diagnostic algorithm for the diagnosis of cryptogenic organising pneumonia (COP). BAL: bronchoalveolar lavage; COVID-19: coronavirus disease 2019; CTD: connective tissue disease; HP: hypersensitivity pneumonitis; HRCT: high-resolution computed tomography; Ig: immunoglobulin; ILD: interstitial lung disease; IPF: idiopathic pulmonary fibrosis; MDD: multidisciplinary discussion; UIP: usual interstitial pneumonitis. #: Raghu [34]; ¶: Raghu [35]; +: Crouser [36].
Tables
- TABLE 1
Conditions associated with organising pneumonia (OP)#
Connective tissue disorders Hypersensitivity pneumonitis (acute) Adverse drug reactions Bone marrow, stem cell or solid organ transplantation Infection Airway diseases complicated by infection Airway obstruction (distal changes) Inhalation injury Aspiration syndromes Chronic eosinophilic pneumonia Radiation pneumonitis Inflammatory bowel disease Neoplasms and myeloproliferative disorders Organising diffuse alveolar damage Coexistent with pathologic changes of IIP (e.g. UIP or NSIP) Acute exacerbation of IPF (OP lesions superimposed on chronic UIP pattern) Proximal bronchial obstruction (OP found distal to focus of obstruction) Miscellaneous Immunodeficiency syndromes Cryoglobulinemia Granulomatosis with polyangiitis Other vasculitis IIP: idiopathic interstitial pneumonia; UIP: usual interstitial pneumonia; NSIP: nonspecific interstitial pneumonia; IPF: idiopathic pulmonary fibrosis. #: conditions other than cryptogenic organising pneumonia (idiopathic OP) that have been associated with histopathologic findings of OP in lung tissue specimens.
- TABLE 2
Radiographic imaging patterns of organising pneumonia
Consolidation Subpleural and/or peribronchial Mid to lower lung zone predominance Can be perilobular Opacities may migrate, wax, wane or disappear Spontaneous regression of consolidated areas may occur Combination of bilateral subpleural consolidation and mid to lower zone predominance observed in majority of patients Other patterns Focal with single nodule or mass Nodular (variable size, can be solitary or multiple) Reversed halo sign (ground-glass opacity, surrounded by a crescent or ring of consolidated parenchyma) Ground-glass opacities (usually bilateral, patchy, seen in up to 90% of patients with cryptic organising pneumonia) Parenchymal bands (often associated with multifocal consolidations) Perilobular (arcade-like or polygonal opacities that are poorly defined and border secondary pulmonary lobules) Fibrotic Reticular opacities with basilar predominance, architectural distortion and superimposed alveolar opacities Honeycomb change, traction bronchiectasis Rare changes Diffuse micronodules (centrilobular or peribronchial) Mediastinal lymph node enlargement Pleural effusion - TABLE 3
Relapses in patients treated with corticosteroids
First author [ref.] Patients n# Number relapsed Length of follow-up Time to relapse Fatal outcomes Additional data Lazor [44] 48 28 (58%) with ≥1 relapse (68% still under treatment at 1st relapse) 35±31 months (median 23) 8±9 months (median 5; range 2–46) No deaths attributable to COP or relapse 9 (19%) with ≥3 relapses
Relapses beyond 15 months of first relapse were rareLohr [45] 20 4 (13%) 3.4 years (median) NG 10 out of 37 at 10.5 years (5 pulmonary) 5-year survival: 73% Zhou [47] 73 23 (31.5%) 50+27 months (range 9–96 months) ≤6 months in 8 of 13 following CS cessation None Fever, elevated C-reactive protein and worse DLCO associated with relapse Barroso [48] 33 18 (56%) out of 32 responding to CS (all responded to additional therapy) 54±40 months <6 months in 8 (44%)
≤1 year in 14 (78%)
Mean time to first relapse: 10±12 months (range 2–54)7 (none due to COP recurrence; infection in 1) Multifocal opacities predicted relapse
Shortened CS maintenance (or lower dose) associated with relapse
More rapid CXR normalisation when treated for relapseYoo [49] 73 14 (19%) 38.2 months (range 13–69) NG Disease-related death in 11 patients 36 received prednisolone only
37 also received a cytotoxic agentZhang [50] 53 35 (70%) NG NG 3 patients 50 patients treated with CS
Relapsers responded to increased CS
98.3% 5-year survivalDrakopanagiotakis [51] 40 13 (43%) out of 30 within 1 year NG NG 1-year mortality: 2 (5.3%) In-hospital mortality 5.7% Onishi [52] 40 15 (38%) NG NG NG BAL neutrophilia and high levels of tissue fibrin deposits correlated with relapse Saito [53] 33 10 (30.3%) NG 476±445 days (range 17–682 days) NG Bilateral shadowing and traction bronchiectasis predictive of relapse Nishino [54] 14 7 (50%) 42 (5–84) months NG NG Relapse associated with multifocal intra-alveolar fibrin deposits and more extensive involvement on chest imaging COP: cryptogenic organising pneumonia; NG: not given in manuscript; CS: corticosteroids; DLCO: diffusing capacity of the lung for carbon monoxide; CXR: chest radiograph; BAL: bronchoalveolar lavage. #: patients with COP treated with CS.
