Understanding the Lymphatics: Review of the N Category in the Updated TNM Staging of Cancers of the Digestive System.

The N category has been significantly updated in the 8th edition of the American Joint Committee on Cancer's TNM classification. To ensure correct tumor staging, prognosis, and management, it is critical to be aware of these changes. This article reviews the updated N category, organ-specific regional lymph nodes, and lymphatic drainage pathways for cancers of the digestive system from the esophagus to the anal canal. Detection of lymph node involvement may be challenging, and knowledge of nodal characteristics, lymphatic drainage pathways, and imaging modalities is essential to optimize detection rate to ensure accurate staging, prognosis estimation, and streamlined management.