Lymph nodes

In addition to the circulatory system that irrigates the walls of the colon and rectum, there is also a network of lymphatic vessels and capillaries covering the colon.

The lymphatic system drains excess fluid from the cells, in the process carrying material discarded by these. In the liver and small intestine gathers fat and proteins absorbed from food.

Throughout the body, the lymphatic system also works as a barrier against disease, as the lymph carries bacteria and viruses from everywhere in the body to be destroyed in the lymph nodes 

Despite this protective role, when there is cancer the lymphatic vessels that can contribute to spreading the disease by acting as an open door into the body to the malignant cells. 

As a result, besides removing the tumor, cancer treatments often also take nearby lymphatic vessels and nodes to prevent the disease from spreading. Biopsy of the removed lymph nodes helps to understand how advanced is the disease.