Initial Pulmonary Nodule Management for the Generalist: A Brief Review

Pulmonary nodules, defined as a focal radiographic opacity of 30 mm in mean diameter or less, are identified in nearly a quarter of computed tomography (CT) scans, with more than 1.5 million nodules detected on CT annually in the United States. Approximately 95% of nodules are benign, yet the probability of malignancy balanced with the potential harm from pursuit of benign nodules guides management. Patient-specific features including smoking history, infectious or inflammatory signs and symptoms, personal or family history of malignant disease, and history of autoimmune disease should be considered. In addition, radiographic features of the pulmonary nodules should be assessed, including size, attenuation (solid, part-solid, ground-glass), margins, location, calcification or fat, and growth rate or lack of growth compared with prior images. These aspects influence estimation of malignancy probability, which can also be approximated by the Mayo Clinic model, Brock University cancer prediction equation, or others. Low-probability nodules can be monitored with serial CT imaging, whereas high-probability nodules may be managed by proceeding directly to biopsy or resection. Management of intermediate-probability nodules can include surveillance imaging, further testing such as fluorodeoxyglucose positron emission tomography, or biopsy, depending on patient- and nodule-specific factors and preferences. Nodules in the 8- to 30-mm range or demonstrating significant growth should prompt referral to a pulmonologist.