Lymphatics

In general, the lymphatic organization in the pelvis and perineum is best remembered by following the vasculature (Fig. 1). Three main groups of lymph nodes drain structures in this region-inguinal nodes, iliac nodes, and para-aortic (lumbar) nodes. Smaller collections of nodes are present within the pelvis, including sacral and pararectal.

Figure 1: Pelvis and perineum lymphatics. A, Male. B, Female.
Note that lymph flow can vary in this region or flow into more than one set of nodes, but the information presented here represents general flow patterns .
A. Inguinal nodes
Organized into superficial and deep inguinal groups, these nodes are arranged along the inguinal ligament. The superficial inguinal nodes drain the majority of the perineum, including the scrotum in males and the anal canal inferior to the pectinate line. A small amount of lymph from the uterus in the region of the round ligament drains through the superficial lymph nodes as well. The spongy urethra in males, glans penis, and clitoris typically drain into deep inguinal nodes.
B. Iliac nodes
Organized into external, internal, and common iliac groups, these nodes are arranged along arteries of the same name. The internal iliac nodes drain selective deep structures of the perineum, anal canal superior to the pectinate line, and pelvic viscera (urinary bladder fundus, cervix, superior vagina, prostate, seminal glands, prostatic, and intermediate urethra in males and the entire urethra in females). External iliac nodes drain most of the uterine body, ductus deferens, and superior urinary bladder.
C. Para-aortic (lumbar) nodes
 these nodes are arranged along the abdominal aorta. Importantly, lymph from both the testes and ovaries-which developed in the abdomen-drain into these nodes.