Pelvic lymph nodes
Pelvic lymph nodes drain lymph from pelvic organs to the paraaortic (lumbar) lymph nodes.
Pelvic lymph nodes are a network of interconnected lymphatic structures located within the pelvic cavity. They serve as critical filtering stations for lymph drained from pelvic organs, perineum, lower abdominal wall, and parts of the lower limb. The major groups include the external iliac, internal iliac, sacral, and inguinal lymph nodes. These nodes are essential in immune surveillance and play a key role in the spread and staging of pelvic malignancies.
Structure
Pelvic lymph nodes are clusters of small, oval-shaped lymphatic tissues. Each node receives afferent lymphatic vessels, filters lymph through cortical and medullary sinuses, and sends efferent vessels to larger lymphatic trunks. The nodes are surrounded by a capsule and consist of lymphoid follicles containing B and T lymphocytes.
Major Groups
- External iliac nodes – Along the external iliac vessels
- Internal iliac nodes – Around the internal iliac artery and its branches
- Sacral nodes – Over the sacrum near the median sacral vessels
- Inguinal nodes – Located inferiorly in the femoral triangle (superficial and deep)
Location
The pelvic lymph nodes are embedded in the connective tissue of the pelvic cavity, often surrounding major arteries and veins. They form chains that follow vascular structures and drain into higher-order lymphatic trunks such as the common iliac and para-aortic nodes.
Node Group | Anatomical Location |
---|---|
External iliac nodes | Along external iliac vessels, anterior and lateral to pelvic brim |
Internal iliac nodes | Medial to external nodes, surrounding branches of internal iliac artery |
Sacral nodes | Posterior pelvic wall, along sacral vessels and anterior to sacrum |
Inguinal nodes | In the femoral triangle, superficial and deep to the fascia lata |
Function
- Lymphatic drainage: Filter lymph from pelvic organs, perineum, genitalia, lower abdominal wall, and lower limbs
- Immune defense: Act as sites of lymphocyte activation and antigen presentation
- Cancer surveillance: First-line nodes for metastasis from pelvic malignancies (e.g., cervical, prostate, bladder cancers)
Drainage Patterns
- Pelvic organs: Primarily to internal and external iliac nodes
- Perineum and lower vagina: To superficial inguinal nodes
- Glans penis/clitoris: To deep inguinal and external iliac nodes
- Uterine fundus (via round ligament): To superficial inguinal nodes
Clinical Significance
- Lymphadenopathy: Enlargement may indicate infection, inflammation, or malignancy
- Sentinel nodes: First nodes involved in metastasis; often biopsied in cancer staging
- Surgical landmarks: Identified and often dissected during oncologic pelvic surgeries
Last updated on May 11, 2025