Regional Lymph Nodes

There are between 100 and 150 lymph nodes in the mesentery of the colon. Regional lymph nodes are the nodes along the colon, plus the nodes along the major arteries that supply blood to that particular colon segment.

Segment Regional Lymph Nodes
Cecum Pericolic, anterior cecal, posterior cecal, ileocolic, right colic
Ascending colon Pericolic, ileocolic, right colic, middle colic
Hepatic flexure Pericolic, middle colic, right colic
Transverse colon Pericolic, middle colic
Splenic flexure Pericolic, middle colic, left colic, inferior mesenteric
Descending colon Pericolic, left colic, inferior mesenteric, sigmoid
Sigmoid colon Pericolic, inferior mesenteric, superior rectal, superior hemorrhoidal, sigmoidal, sigmoid mesenteric
Rectosigmoid Perirectal, left colic, sigmoid mesenteric, sigmoidal, inferior mesenteric, superior rectal, superior hemorrhoidal, middle hemorrhoidal
Rectum Perirectal, sigmoid mesenteric, inferior mesenteric, lateral sacral, presacral, internal iliac, sacral promontory (Gerota's) superior hemorrhoidal, inferior hemorrhoidal
Anus Perirectal, anorectal, superficial inguinal, internal iliac, hypogastric, femoral, lateral sacral

Lymph nodes along a "named vascular trunk" (as defined by the fourth edition of the AJCC staging manual) are those along a vein or artery that carries blood to a specific part of the colon, for example, the inferior and superior mesenteric arteries, sigmoidal artery, left or right colic artery. In the fifth and sixth editions, the location of the nodes does not affect assignment of the N category.

Illustration of colorectal lymph nodes.