Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (764 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Any obstructive lung disease characterized by consolidated formation of granulation tissue polyps within alveolar ducts and alveoli. It is classified as either primary (cryptogenic organizing pneumonia) or secondary organizing pneumonia. Secondary organizing pneumonia after transplantation is called bronchiolitis obliterans syndrome.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Organizing Pneumonias; Pneumonia, Organizing; Secondary Organizing Pneumonia; Organizing Pneumonia, Secondary; Pneumonia, Secondary Organizing; Secondary Organizing Pneumonias.
Where it fits in the MeSH classification
- Broader topics
- Bronchiolitis Obliterans
- Narrower topics
- Bronchiolitis Obliterans Syndrome; Cryptogenic Organizing Pneumonia
Related concepts
- Granulation Tissue
- Alveolar Ducts And Alveoli
Research landscape
PubMed indexes 1,508 records tagged with the MeSH heading “Organizing Pneumonia” (counts retrieved 2026-11-04). 477 of them (31.6%) were published from 2020 onward, and the busiest period so far is 2020 onward with 477 records.
Reviews account for 250 records (16.6%) and meta-analyses for 5. Randomized controlled trials number 10 (0.7%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 221 |
| 2000-2009 | 444 |
| 2010-2019 | 366 |
| 2020 onward | 477 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 250 | 16.6% |
| Meta-analyses | 5 | 0.3% |
| Randomized controlled trials | 10 | 0.7% |
Method: PubMed query "Organizing Pneumonia"[MeSH Terms] with publication-type and date filters, retrieved 2026-11-04.
Reading the evidence in respiratory medicine
Research on airway and lung disease mixes lung-function tests, symptom diaries, imaging and hospital records, so what was measured and in whom matters as much as the result. Many conditions here, such as asthma and COPD, vary between people and over time, and exposure studies (smoking, pollution, workplace dust) show association rather than proof of cause. Nothing on this page is advice about treatment or inhalers; anyone with breathing difficulty should seek care from a qualified clinician. Check how the condition was defined, the severity of the people studied and whether outcomes were symptoms, lung function or hospital admissions.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Relationship between radiation pneumonitis and organizing pneumonia after radiotherapy for breast cancer | 2013 | Research article Design not recorded in structured metadata | 31 | cc by PMID 23497657 · DOI · PMC3605133 |
| Complex interactions of cellular players in chronic Graft-versus-Host Disease | 2023 | Review article Design not recorded in structured metadata | 23 | cc by PMID 37435079 · DOI · PMC10332803 |
| Patient-reported symptom burden and impact on daily activities in chronic graft-versus-host disease | 2023 | Research article Design not recorded in structured metadata | 22 | cc by PMID 36394207 · DOI · PMC9939096 |
| Perioperative Treatment of Metachronous Multiple Lung Cancer with Organizing Pneumonia: A Case Report | 2025 | Research article Design not recorded in structured metadata | 0 | cc by PMID 40803838 · DOI · PMC12352969 |
Relationship between radiation pneumonitis and organizing pneumonia after radiotherapy for breast cancer [1]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundRadiation pneumonitis (RP) and organizing pneumonia (OP) are the two main types of lung damage that can occur after lung irradiation.
- Closing excerpt
- All OP lesions developed near the site of RP.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (148 words)
BackgroundRadiation pneumonitis (RP) and organizing pneumonia (OP) are the two main types of lung damage that can occur after lung irradiation. The goal of this study was to evaluate the relationship between RP and OP after irradiation for breast cancer.MethodsFour hundred and twenty-eight patients who underwent radiotherapy for breast cancer were identified. The whole breast was irradiated with two tangential photon beams. Chest computed tomography (CT) scan were performed when patients showed any symptoms that were suspicious for pneumonitis.ResultsFive patients (1.2%) were diagnosed with OP. All five patients showed ground glass opacities and consolidation of the border of the lesion of RP in the radiation fields. Infiltration of OP spread from the site of RP to the hilum of the ipsilateral lung. Between RP and OP, a free region space (FRS) could be detected.ConclusionsOP is closely related to RP. All OP lesions developed near the site of RP.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 23497657 · DOI · PMC3605133
Complex interactions of cellular players in chronic Graft-versus-Host Disease [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Chronic Graft-versus-Host Disease is a life-threatening inflammatory condition that affects many patients after allogeneic hematopoietic stem cell transplantation.
- Closing excerpt
- Lastly, we discuss the importance of understanding systemic and local aberrant cell communication during disease for defining better biomarkers and therapeutic targets, eventually enabling the design of personalized treatment schemes.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (158 words)
Chronic Graft-versus-Host Disease is a life-threatening inflammatory condition that affects many patients after allogeneic hematopoietic stem cell transplantation. Although we have made substantial progress in understanding disease pathogenesis and the role of specific immune cell subsets, treatment options are still limited. To date, we lack a global understanding of the interplay between the different cellular players involved, in the affected tissues and at different stages of disease development and progression. In this review we summarize our current knowledge on pathogenic and protective mechanisms elicited by the major involved immune subsets, being T cells, B cells, NK cells and antigen presenting cells, as well as the microbiome, with a special focus on intercellular communication of these cell types via extracellular vesicles as up-and-coming fields in chronic Graft-versus-Host Disease research. Lastly, we discuss the importance of understanding systemic and local aberrant cell communication during disease for defining better biomarkers and therapeutic targets, eventually enabling the design of personalized treatment schemes.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 37435079 · DOI · PMC10332803
Patient-reported symptom burden and impact on daily activities in chronic graft-versus-host disease [3]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundChronic graft-versus-host disease (GVHD) is a potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT) treatment for hematologic malignancies.
- Closing excerpt
- Effective strategies to mitigate chronic GVHD symptoms are needed to improve QoL among HSCT survivors.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (309 words)
BackgroundChronic graft-versus-host disease (GVHD) is a potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT) treatment for hematologic malignancies. There are limited patient-reported data concerning symptom burden and effects on activities of daily living (ADL).MethodsThe cross-sectional Living With Chronic GVHD Patient Survey was administered online in the United States (May-August 2020) to participants aged ≥18 years who underwent allogeneic HSCT, were diagnosed with chronic GVHD by a healthcare provider, and self-reported active chronic GVHD (within past 5 years). Information on patient demographics, disease characteristics, symptom burden, and ability to perform ADL was collected. Symptom burden was assessed using the validated Lee Symptom Scale (range from 0-100 with higher scores indicating greater burden). All data were summarized using descriptive statistics; no formal statistical comparisons were conducted.ResultsOut of 580 participants who entered the survey screener, 165 participants (28.4%) across 33 states fulfilled all study eligibility criteria, completed the entire survey, and were included (age: mean [SD], 53.7 (13.8) years; median [range], 57.0 [18-78] years; female, n = 105 [63.6%]; White, n = 137 [83.0%]). Respondents described their chronic GVHD severity primarily as moderate (n = 54 [32.7%]) or severe (n = 102 [61.8%]) at the time when symptoms were at their worst. One-third of respondents (33.9%) indicated that their chronic GVHD symptoms were at their worst for ≥1 year in duration. Mean (SD; range) Lee Symptom Scale score was 44.8 (19.4; 2-100); 44% of respondents considered "dry eye" the most burdensome symptom. Almost half of respondents (n = 73 [44.2%]) rated their overall quality of life (QoL) as poor. Participants reported a detrimental impact of symptoms on ADL, including basic activities (eg, eating, personal hygiene, dressing).ConclusionsSurvey respondents self-reported high chronic GVHD symptom burden and felt that their symptoms severely interfered with physical function and ADL. Effective strategies to mitigate chronic GVHD symptoms are needed to improve QoL among HSCT survivors.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 36394207 · DOI · PMC9939096
Perioperative Treatment of Metachronous Multiple Lung Cancer with Organizing Pneumonia: A Case Report [4]
Abstract reading summary — source excerpts
- Opening excerpt
- We report a rare case of the independent coexistence of lung cancer and organizing pneumonia (OP) in different lobes of the right lung in a 67-year-old man with a history of left upper lobectomy.
- Closing excerpt
- This case highlights the need for individualized perioperative management in patients with complex pulmonary pathology.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (149 words)
We report a rare case of the independent coexistence of lung cancer and organizing pneumonia (OP) in different lobes of the right lung in a 67-year-old man with a history of left upper lobectomy. Computed tomography revealed a lesion consistent with OP in the right upper lobe and a suspicious shadow in the right lower lobe, which was diagnosed as squamous cell carcinoma via bronchoscopic biopsy. The patient underwent right lower lobectomy and partial resection of the right upper lobe under left one-lung ventilation. Empirical corticosteroids were administered preoperatively, followed by a brief postoperative course for 3 days after pathological confirmation of OP to reduce complications such as bronchial fistula, then transitioned to macrolide therapy for 3 months. Fourteen months postoperatively, OP had not recurred, although bone metastases developed and responded well to chemoradiotherapy. This case highlights the need for individualized perioperative management in patients with complex pulmonary pathology.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40803838 · DOI · PMC12352969
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Cryptogenic organising pneumonia [5]
- Research article Bronchiolitis obliterans organizing pneumonia [6]
- Research article Organising pneumonia [7]
- Research article Bronchiolitis obliterans organizing pneumonia [8]
- Research article Bronchiolitis obliterans syndrome (BOS), bronchiolitis obliterans organizing pneumonia (BOOP), and other late-onset noninfectious pulmonary complications following allogeneic hematopoietic stem cell transplantation [9]
- Research article Cryptogenic Organizing Pneumonia [10]
References
- Oie Y, Saito Y, Kato M, Ito F, Hattori H, Toyama H, et al.. Relationship between radiation pneumonitis and organizing pneumonia after radiotherapy for breast cancer. . 2013. PMID 23497657 · DOI · PMC3605133
- Gail LM, Schell KJ, Łacina P, Strobl J, Bolton SJ, Steinbakk Ulriksen E, et al.. Complex interactions of cellular players in chronic Graft-versus-Host Disease. . 2023. PMID 37435079 · DOI · PMC10332803
- Yu J, Hamilton BK, Turnbull J, Stewart SK, Vernaya A, Bhatt V, et al.. Patient-reported symptom burden and impact on daily activities in chronic graft-versus-host disease. . 2023. PMID 36394207 · DOI · PMC9939096
- Takehara H, Kodama K, Momozane T, Kido K. Perioperative Treatment of Metachronous Multiple Lung Cancer with Organizing Pneumonia: A Case Report. . 2025. PMID 40803838 · DOI · PMC12352969
- Cordier JF. Cryptogenic organising pneumonia. Eur Respir J. 2006. PMID 16880372 · DOI
- Epler GR. Bronchiolitis obliterans organizing pneumonia. Semin Respir Infect. 1995. PMID 7569401 · DOI
- Cordier JF. Organising pneumonia. Thorax. 2000. PMID 10722773 · DOI · PMC1745738
- Epler GR. Bronchiolitis obliterans organizing pneumonia. Arch Intern Med. 2001. PMID 11176728 · DOI
- Yoshihara S, Yanik G, Cooke KR, Mineishi S. Bronchiolitis obliterans syndrome (BOS), bronchiolitis obliterans organizing pneumonia (BOOP), and other late-onset noninfectious pulmonary complications following allogeneic hematopoietic stem cell transplantation. Biol Blood Marrow Transplant. 2007. PMID 17580252 · DOI
- King TE, Lee JS. Cryptogenic Organizing Pneumonia. N Engl J Med. 2022. PMID 35294814 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-11-04; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-11-04.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.