From the Guidelines
A pulmonary nodule is defined as a well or poorly defined rounded opacity measuring less than 3 cm in diameter. These nodules can be either solid, part-solid, or ground-glass on CT, based on their attenuation, allowing for a more accurate assessment of malignancy risk 1. The management of incidental pulmonary nodules is challenging, but guidelines from the Fleischner Society and American College of Chest Physicians (ACCP) have been developed to help manage them based on a nodule's potential for clinically significant disease 1.
Key Characteristics of Pulmonary Nodules
- Typically less than 3 centimeters in diameter
- Can be solid, part-solid, or ground-glass on CT
- Often discovered incidentally during imaging tests performed for other reasons
- Can be solitary or multiple
Risk Factors for Malignancy
- Larger size (especially greater than 8mm)
- Irregular borders
- Growth over time
- Patient factors such as older age, smoking history, or previous cancer
Management
- Follow-up imaging at intervals determined by the nodule's characteristics and the patient's risk factors
- Additional testing such as PET scans or biopsies may be recommended for higher-risk nodules
- Regular follow-up is essential to ensure that even benign nodules do not change in appearance or size over time 1.
The most recent and highest quality study, published in 2023, provides the most up-to-date guidance on the management of incidental pulmonary nodules 1. This study emphasizes the importance of considering a nodule's characteristics and a patient's risk factors when determining the appropriate management strategy. The management of pulmonary nodules should be individualized and based on the latest evidence-based guidelines.
From the Research
Definition of Pulmonary Nodule
- A pulmonary nodule is a small, rounded growth on the lung, which can be detected on computed tomographic (CT) images of the chest 2.
- Pulmonary nodules are identified in approximately 1.6 million patients per year in the US and are detected on approximately 30% of CT images of the chest 2.
- At least 95% of all pulmonary nodules identified are benign, most often granulomas or intrapulmonary lymph nodes 2.
Types of Pulmonary Nodules
- Pulmonary nodules are categorized as small solid (<8 mm), larger solid (≥8 mm), and subsolid 2.
- Subsolid nodules are divided into ground-glass nodules (no solid component) and part-solid (both ground-glass and solid components) 2.
- The probability of malignancy varies by size and type of nodule, with smaller nodules being more likely to be benign 2, 3.
Management of Pulmonary Nodules
- The treatment of an individual with a pulmonary nodule should be guided by the probability that the nodule is malignant, safety of testing, the likelihood that additional testing will be informative, and patient preferences 2.
- Management options include surveillance imaging, positron emission tomography-CT imaging, nonsurgical biopsy with bronchoscopy or transthoracic needle biopsy, and surgical resection 2, 4.
- The choice of a particular biopsy technique depends on the risks/benefits of the procedure, the diagnostic yield, and local expertise 4.