Diagnostic approach to the solitary pulmonary nodule.

The number of solitary pulmonary nodules (SPNs) detected each year is expected to increase dramatically with the implementation of lung cancer screening. Although some will have radiographic features highly specific for benignity, the rest are considered indeterminate and require further investigation. The management options include continued surveillance or immediate diagnostic sampling. The decision to proceed with immediate sampling is determined by nodule characteristics (i.e., density and size), and patient risk factors and preferences. Sampling is achieved either by surgical or by nonsurgical techniques, and the choice between the two is influenced by the probability of malignancy. Surgical methods are preferred in SPNs with high probability of malignancy because they provide both a definitive diagnosis and treatment in a single procedure. In contrast, when the probability of malignancy is low to moderate nonsurgical sampling is preferred. The following is a review of the diagnostic management options available when approaching an SPN.