Commonly encountered difficulties in pathologic staging of lung cancer.

CONTEXT Lung cancer is the leading cause of cancer mortality worldwide. Despite technological, therapeutic, and scientific advances, most patients present with incurable disease and a poor chance of long-term survival. For those with potentially curable disease, lung cancer staging greatly influences therapeutic decisions. Therefore, surgical pathologists determine many facets of lung cancer patient care. OBJECTIVE To present the current lung cancer staging system and examine the importance of mediastinal lymph node sampling, and also to discuss particularly confusing and/or challenging areas in lung cancer staging, including assessment of visceral pleura invasion, bronchial and carinal involvement, and the staging of synchronous carcinomas. DATA SOURCES Published current and prior staging manuals from the American Joint Committee on Cancer and the International Union Against Cancer as well as selected articles pertaining to lung cancer staging and diagnosis accessible through PubMed (National Library of Medicine) form the basis of this review. CONCLUSIONS Proper lung cancer staging requires more than a superficial appreciation of the staging system. Clinically relevant specimen gross examination and histologic review depend on a thorough understanding of the staging guidelines. Common sense is also required when one is confronted with a tumor specimen that defies easy assignment to the TNM staging system.