Contents

Search

pulmonary nodule

Classification: - a solitary pulmonary nodule is a single lesion up to 3 cm in diameter, surrounded by normal lung tissue, & not associated with lymphadenopathy - a lesion larger than 3 cm is considered a lung mass* * pulmonary nodules > 3 cm are presumed malignant until proven otherwise [1] Etiology: 1) see solitary pulmonary nodule 2) solitary or multiple nodules may represent metastases to the lung 3) multiple nodules: Mycobacterium: tuberculosis, Mycobacterium avium complex 4) Pneumocystis pneumonia 5) histoplasmosis 6) hypersensitivity pneumonitis Epidemiology: - > 40% of Danish non-smokers have at least one lung nodule - ~25% have clinically relevant nodules based on low-dose CT [7] Pathology: - a lung cancer is often associated with smaller benign nodules - 35% of pulmonary nodules 8-20 mm surgically excised are benign [4] Special laboratory: - sputum microscopy & culture for tuberculosis - fiberoptic bronchoscopy with biopsy for centrally located lung mass with endobronchial component - navigational bronchoscopy matches diagnostic accuracy of transthoracic needle biopsy for peripheral pulmonary nodules with fewer complications [9] - see lung carcinoma for suspected lung cancer - needle aspiration of suspicious peripheral lymph node [1] Radiology: - computed tomography (non-contrast) [1] - low-dose CT as effective as standard CT [1] - PET scan - a solitary hypermetabolic lung mass in a patient at risk for NSCLC obviates the need for biopsy unless it cannot be removed surgically* [1] - unlikely to detect lesions < 1 cm in size [1] - specificity of fludeoxyglucose 18F-PET lower in areas of endemic infectious disease [3] * in contrast, the National Comprehensive Cancer Network (NCCN) guidelines recommends a tissue diagnosis using the least invasive method with the highest diagnostic yield. [10] Management: - also see solitary pulmonary nodule - 1 predominant nodule > 1 cm in diameter & >= smaller nodules - biopsy the largest nodule - endobronchial ultrasound-guided transbronchial needle biopsy if mediastinal lymphadenopathy in addition to pulmonary nodule [1,8] - biopsy a lung mass - incidentalomas < 1 cm in size (regardless of number) - high risk patients (smokers): follow-up imaging in 12 months - low risk patients: no follow-up needed [1,2]

Related

rheumatoid nodule

Specific

centrilobular pulmonary nodule solitary pulmonary nodule; pulmonary coin lesion

General

nodule lung disease thoracic mass lesion

References

  1. Medical Knowledge Self Assessment Program (MKSAP) 15, 16, 17, 18, 19. American College of Physicians, Philadelphia 2009, 2012, 2015, 2018, 2022. - Medical Knowledge Self Assessment Program (MKSAP) 20 American College of Physicians, Philadelphia 2025
  2. MacMahon H, Austin JH, Gamsu G, Herold CJ et al Guidelines for management of small pulmonary nodules detected on CT scans: a statement from the Fleischner Society. Radiology. 2005 Nov;237(2):395-400. PMID: 16244247
  3. Deppen SA et al Accuracy of FDG-PET to Diagnose Lung Cancer in Areas With Infectious Lung DiseaseA Meta-analysis. JAMA. 2014;312(12):1227-1236 PMID: 25247519 JAMA. 2014;312(12):1227-1236
  4. Tanner NT et al. Management of pulmonary nodules by community pulmonologists: A multicenter observational study. Chest 2015 Dec; 148:1405. PMID: 26087071 http://journal.publications.chestnet.org/article.aspx?articleid=2337001 - Wiener RS et al. Pulmonologists' reported use of guidelines and shared decision-making in evaluation of pulmonary nodules: A qualitative study. Chest 2015 Dec; 148:1415 PMID: 25789979 http://journal.publications.chestnet.org/article.aspx?articleid=2209998
  5. Gould MK, Donington J, Lynch WR et al Evaluation of individuals with pulmonary nodules: when is it lung cancer? Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest. 2013 May;143(5 Suppl):e93S-e120S. Review. PMID: 23649456 Free PMC Article
  6. NEJM JWatch Question of the Week. March 27, 2018 https://knowledgeplus.nejm.org/question-of-week/562/
  7. Cai J, Vonder M, Pelgrim GJ Distribution of Solid Lung Nodules Presence and Size by Age and Sex in a Northern European Nonsmoking Population. Radiology. 2024 Aug;312(2):e231436. PMID: 39136567 https://pubs.rsna.org/doi/10.1148/radiol.231436
  8. Torre M, Reda M, Musso V, et al. Diagnostic accuracy of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) for mediastinal lymph node staging of lung cancer. Mediastinum. 2021;5:15. PMID: 35118321
  9. Lentz RJ et al. Navigational bronchoscopy or transthoracic needle biopsy for lung nodules. N Engl J Med 2025 Jun 5; 392:2100. PMID: 40387025
  10. Reily GJ et al Non-Small Cell Lung Cancer. National Comprehensice Cancer Network. Nov 6, 2025 https://www.nccn.org/professionals/physician_gls/pdf/nscl.pdf