Approach to the patient with multiple lung nodules.

It can be difficult to determine whether a patient with more than a single, "solid" lung nodule suspicious for malignancy is suffering from synchronous primary tumors or intrapulmonary metastasis. For this reason, if resection can be performed an aggressive approach is often warranted after demonstrating no mediastinal nodal disease. Increasing evidence suggests that the survival of a patient with a single, invasive lepidic-predominant adenocarcinoma depends on the stage of the invasive tumor, not on the presumed multiple in situ tumors. A suggested clinical approach to each of these types of multifocal tumors, solid and lepidic, is proposed in this article.