Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 9-16: Solitary Pulmonary Nodule + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ An isolated, < 3-cm rounded opacity on chest imaging that is outlined by normal lung and not associated with infiltrate, atelectasis, or adenopathy +++ General Considerations ++ Most are asymptomatic and represent an unexpected finding on chest radiography or CT scanning Associated with a 10–68% risk of malignancy Most benign nodules are infectious granulomas; benign neoplasms such as hamartomas account for < 5% of solitary nodules Symptoms alone rarely establish etiology, but can be used with imaging data to assess the probability of malignancy The goal of evaluation is to determine the probability of malignancy in any nodule in order to justify resection or biopsy versus observation +++ Demographics ++ Malignant nodules are rare in persons under age 30 Over age 30, risk for malignancy increases with age Smokers are at increased risk, with the likelihood of cancer increasing with the number of daily cigarettes smoked A history of malignancy increases the likelihood that a nodule represents cancer + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Solitary nodules are discovered incidentally on imaging studies +++ Differential Diagnosis ++ Granulomatous disease Benign neoplasm Bronchogenic carcinoma Granuloma (tuberculous, fungal) Lung abscess Hamartoma Metastatic cancer Arteriovenous malformation Resolving pneumonia Rheumatoid nodule Pulmonary infarction Carcinoid Pseudotumor (loculated fluid in a fissure) + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ Sputum cytology is highly specific, but insensitive for detecting malignant nodules +++ Imaging Studies ++ Comparison with prior imaging studies allows estimation of doubling time: rapid doubling time (< 30 days) suggests infection; slow doubling time (< 465 days) suggests benignity High-resolution CT (HRCT) scanning for any nodule Increasing size on CT scan correlates with risk of malignancy 1% malignancy rate for 2–5 mm 24% for 6–10 mm 33% for 11–20 mm 80% for 21–45 mm CT features suggesting malignancy Spiculations or a peripheral halo Sparse stippled or eccentric calcifications Thick-walled (> 16 mm) cavitary lesions CT features associated with benign processes Smooth, well-defined margins Dense central or laminar calcifications Positron emission tomography (PET) is highly sensitive (85–97%) and specific (70–85%) for detecting malignant nodules and is incorporated in many diagnostic algorithms with HRCT +++ Diagnostic Procedures ++ In patients with a high probability of malignancy, biopsies rarely yield a specific benign diagnosis Bronchoscopy yields a diagnosis in 10–80%, depending on the size and location of the nodule; complications are rare Transthoracic needle aspiration (TTNA) has a diagnostic yield of 50–97%, with a 30% risk of pneumothorax Video-assisted thoracoscopic surgery (VATS) is used for initial evaluation of intermediate risk nodules; frozen sections can direct treatment in the operating room + Treatment Download Section PDF Listen +++ +++ Therapeutic Procedures ++ A probability of malignancy should be assigned to each nodule based on clinical and radiographic features Watchful waiting is appropriate for patients with low probability (< 5%) of malignancy (2 years, benign calcification pattern) Resection is indicated for patients with a high probability (> 60%) of malignancy and no contraindications to surgery Optimal management of patients with an intermediate probability (5–60%) of malignancy is controversial; bronchoscopy, transthoracic needle biopsy, VATS, PET scan, and contrast-enhanced HRCT are used +++ Surgery ++ Lobectomy and lymph node sampling Done when nodule is malignant Less common when PET scanning is available May be performed thoracoscopically or by standard thoracotomy + Outcome Download Section PDF Listen +++ +++ Follow-Up ++ For a nodule with a low probability of malignancy, patients should have chest radiograph every 3 months for 1 year, then every 6 months for 1 year +++ When to Refer ++ For specialized diagnostic procedures such as bronchoscopy, transthoracic needle aspiration, or thoracoscopic surgery + References Download Section PDF Listen +++ + +Chilet-Rosell E et al. The determinants of lung cancer after detecting a solitary pulmonary nodule are different in men and women, for both chest radiograph and CT. PLoS One. 2019 Sep 11;14(9):e0221134. [PubMed: 31509550] + +Cruickshank A et al. Evaluation of the solitary pulmonary nodule. Intern Med J. 2019 Mar;49(3):306–15. [PubMed: 30897667] + +Huang HL et al. Surgical resection is sufficient for incidentally discovered solitary pulmonary nodule caused by nontuberculous mycobacteria in asymptomatic patients. PLoS One. 2019 Sep 12;14(9):e0222425. [PubMed: 31513659] + +Khan T et al. Diagnosis and management of peripheral lung nodule. Ann Transl Med. 2019 Aug;7(15):348. [PubMed: 31516894] + +Nasim F et al. Management of the solitary pulmonary nodule. Curr Opin Pulm Med. 2019 Jul;25(4):344–53. [PubMed: 30973358] + +Tang K et al. The value of 18F-FDG PET/CT in the diagnosis of different size of solitary pulmonary nodules. Medicine (Baltimore). 2019 Mar;98(11):e14813. [PubMed: 30882661]