Evaluation and management of the solitary pulmonary nodule.

The finding of a solitary pulmonary nodule (SPN) on a chest radiograph is a common problem in pulmonary medicine. SPNs are seen in 0.09 to 0.2% of chest radiographs and are caused by a variety of conditions, ranging from benign granulomas to lung cancer (1–3). Because solitary nodules are often malignant and because 5-yr survival after resection of a solitary bronchogenic carcinoma is 40 to 80%, it is important to promptly identify malignant nodules to ensure optimal treatment (4, 5). Similarly, it is important to avoid the morbidity and mortality associated with thoracotomy in patients with benign disease. Therefore, the goal of the evaluation and management of solitary pulmonary nodules is to promptly identify and bring to surgery all patients with operable malignant nodules while avoiding thoracotomy in patients with benign nodules. Traditional approaches have emphasized assessment of the probability of malignancy, the so-called Bayesian approach. The Bayesian approach estimates the prevalence of malignancy in the population, assesses risk factors predictive of malignancy as demonstrated by history and chest radiograph, and selects a management strategy based on the adjusted probability of malignancy. The development of new diagnostic tests and surgical techniques requires that this traditional approach be reevaluated. This commentary will focus on the role of newer imaging methods in this process and on strategies for SPNs of indeterminate origin.