Anatomic Study of Lateral Pelvic Lymph Nodes: Implications in the Treatment of Rectal Cancer

Abstract

The mean number of lymph nodes found in lateral pelvic wall compartments was 28.6 per specimen. The group containing most lymph nodes lies in the obturator fossa. Complete excision of hypogastric lymph nodes demands a deep pelvic dissection of neurovascular structures.

Controversies in the Management of Lateral Pelvic Lymph Nodes in Patients With Advanced Rectal Cancer: East or West?

“…They classified the nodes into three regions: presacral, hypogastric, and obturator group. This study showed that the highest incidence of nodal involvement was found along the internal pudendal artery region, the internal iliac artery region and the obturator region, considering these regions combined as a "vulnerable field" (11). The lymph nodes from the internal iliac artery were found predominantly above the pelvic nerve plexus but reaching the deep pelvic veins, hence, demanding a deep pelvic dissection of the neurovascular structures (11).…”

“…It is believed that disease in this area is because of the lymphatic drainage from the lower rectum exceeds the mesorectum through the lateral ligament and then along the internal iliac artery and consequently into the obturator space. This theory explains why the obturator region has the highest rate of nodal involvement and it should be examined as a significant area of cancer spread in these tumors (11).…”

Morphological characteristics of lateral pelvic lymph nodes in rectal carcinoma

“…There was only one report from Canessa et al [21] describing size of lateral pelvic lymph nodes in diseasefree cadavers. However, they did not evaluate tumorbearing lateral pelvic lymph nodes.…”

Outcomes of Surgery Alone for Lower Rectal Cancer With and Without Pelvic Sidewall Dissection

“…The next most frequent site of lateral pelvic lymph node metastasis was the obturator area. Canessa et al 17 reported an anatomic study using cadaveric dissection, in which most of the metastatic lymph nodes found in the lateral pelvic area were located in the obturator area. Therefore, we believe that the next AJCC cancer staging manual should mention not the external iliac area but the obturator area as a site of regional lymph node metastasis in lower rectal cancer.…”