Mapping nodal metastasis in GI cancers: key lymphatic stations and dissemination patterns.

Gastrointestinal (GI) cancers are a leading cause of cancer-related mortality worldwide. Accurate identification of lymphatic spread is essential for staging, prognosis, and treatment planning. The first metastatic lymph nodes vary depending on the primary tumor site, representing the initial echelon of nodal involvement. This pictorial essay reviews the lymphatic drainage patterns of major gastrointestinal cancers-including esophageal, gastric, pancreatic, hepatobiliary, and colorectal tumors-highlighting key nodal stations commonly involved in metastatic spread emphasizing their diagnostic and clinical relevance. By integrating multimodality imaging findings, we highlight key lymph node groups involved in metastasis, discuss their anatomical significance, and illustrate their appearance on computed tomography (CT) and magnetic resonance imaging (MRI). Understanding these patterns is critical for optimizing oncologic management.