From the Guidelines
The external iliac lymph nodes primarily receive lymphatic drainage from the lower limbs, external genitalia, pelvic viscera, and lower abdominal wall. Specifically, they collect lymph from the lower extremities (legs, feet), gluteal region (buttocks), external genitalia (including the penis, scrotum in males, and vulva, lower vagina, and clitoris in females), lower anterior abdominal wall below the umbilicus, and portions of pelvic organs such as the bladder, prostate, cervix, and upper vagina 1. These nodes are located along the external iliac vessels in the pelvis and form an important part of the lymphatic drainage pathway. They ultimately drain into the common iliac lymph nodes, which then drain into the lumbar (para-aortic) lymph nodes. Understanding this drainage pattern is clinically significant because metastatic spread of cancers from these organs often follows lymphatic pathways, making the external iliac nodes potential sites for cancer metastasis from pelvic organs or lower extremities. Some studies suggest that the external iliac nodes may also be involved in the drainage of other pelvic organs, such as the rectum, although this is less common 1. In general, the external iliac lymph nodes play a crucial role in the lymphatic drainage of the pelvis and lower extremities, and their involvement in cancer metastasis can have significant implications for patient outcomes. Key points to consider include:
- The external iliac lymph nodes receive lymphatic drainage from a variety of sources, including the lower limbs, external genitalia, and pelvic viscera.
- These nodes are located along the external iliac vessels in the pelvis and drain into the common iliac lymph nodes.
- Understanding the drainage pattern of the external iliac lymph nodes is important for identifying potential sites of cancer metastasis.
- The external iliac nodes may be involved in the drainage of other pelvic organs, such as the rectum, although this is less common.
From the Research
Organs that Drain into External Iliac Lymph Nodes
The external iliac lymph nodes receive lymphatic drainage from several organs and areas of the body, including:
- The lower limb, with the first route of drainage being anterior and along the external iliac vessels 2
- The uterus, with the corpus uterinum draining to lymph nodes located in the lateral part of the parametrium and under the external iliac vein, and the cervix draining to lymph nodes located on the posterior aspect of the external iliac vein, especially near the hypogastric artery origin 3
- The prostate, with drainage primarily from the periprostatic area to the deep branches of the internal iliac lymphatics, and subsequent spread to the proximal external iliac lymphatics 4
Lymphatic Drainage Pathways
The lymphatic drainage pathways of the external iliac lymph nodes involve:
- Afferent vessels issued from the different pelvic organs, including the genital and urinary organs and the digestive tract 5
- Efferent vessels running towards lymphatic collectors, situated above them, and which end in the lymphatic lumbar duct 5
- Connections between the external iliac lymph nodes and aortal and lumbar nodes of the opposite side, although these are relatively rare (occurring in 3% of cases) 2
Clinical Significance
Understanding the lymphatic drainage of the external iliac lymph nodes is important for: