Lymphatic System and Disease: Role in Pathogen and Cancer Spread

The lymphatic system (vessels and nodes) drains tissue fluid and mounts immune responses. However, it can also transport pathogens and cancer cells:

• Pathogens enter via skin breaks or mucosal tracts, reach nodes, and may evade immunity to spread.
• Cancer cells detach from primary tumors, travel via lymphatics to nodes, and if not destroyed, metastasize (lymphatic metastasis).

Thus, the lymphatic system is both a defense pathway and a route for disease dissemination.