The diagnostic frequency of multiple pulmonary tumor nodules has increased significantly in clinical practice. Among patients with multiple pulmonary nodules, distinguishing between separate primary lung carcinomas and intrapulmonary metastases is critical for accurate tumor staging, therapeutic decision-making, and prognostic evaluation. The consensus document "Differentiating separate primary lung adenocarcinomas from intrapulmonary metastases with emphasis on pathological and molecular considerations: Recommendations from the International Association for the Study of Lung Cancer Pathology Committee" highlights the pivotal role of integrated pathological and molecular analyses in diagnosing and differentiating primary lung adenocarcinomas from intrapulmonary metastatic lesions. It further proposes a combined four-step histologic and molecular classification algorithm for addressing multiple pulmonary tumor nodules of adenocarcinoma histology, providing clinicians with enhanced diagnostic tools to refine staging accuracy, guide therapeutic strategies, and improve prognostic predictions for lung adenocarcinoma. Building on current advancements in global research, this article offers a comprehensive interpretation of the consensus recommendations.