The following groups of pelvic lymph nodes should be considered:
1. Common iliac lymph nodes: between the aortic bifurcation and the common iliac vessel bifurcation.
- Medial, lateral, and lumbosacral subdivisions
- lumbosacral subdivision refers to lymph nodes in the lumbosacral fossa (triangular region bounded by common iliac vessels medially, psoas muscle laterally, and lower lumbar/upper sacral vertebral bodies posteriorly)
- Medial and lateral subdivisions
- obturator nodes are considered part of the medial subdivision and gather their name from proximity to the obturator internus muscle
- Anterior, lateral sacral, and presacral subdivisions
- hypogastric is a term used by some to describe the most cephalic of the internal iliac lymph nodes while others use the term to describe all internal iliac lymph nodes as a group
- Superficial subdivision nodes lie anterior to the inguinal ligament and femoral vessels
- Deep subdivision lymph nodes are enclosed within the femoral sheath
McMahon CJ, Rofsky NM, Pedrosa I. Lymphatic metastases from pelvic tumors: anatomic classification, characterization, and staging. Radiology 2010;254:31-46.