Treatment of Multifocal Disease: When Is Intervention Really Needed?

Multiple lung nodules, ranging from nonsolid to pure solid, are common and can represent neoplastic and nonneoplastic etiologies. Among primary lung neoplasms, they can represent separate primary lung cancers (SPLCs) or intrapulmonary metastases. Multiple subsolid nodules can represent a clinical subtype of SPLCs characterized by indolent growth and excellent prognosis. Management should be appropriately nuanced to avoid overdiagnosis and overtreatment. This critical review covers concepts and terminology, the initial assessment, diagnosis and treatment principles, and areas for future study. Ultimately, management is guided by the most suspicious nodule(s) and should be appropriately tailored to the patient context with multidisciplinary guidance.