Which lymph nodes are commonly swollen in patients with cervical neoplasia?

Lymph Node Involvement in Cervical Neoplasia

In cervical neoplasia, the most commonly involved lymph nodes are the obturator, external iliac, and parametrial lymph nodes, which represent the primary drainage pathway for the cervix. 1, 2

Primary Lymphatic Drainage Pathways

• The most common pattern of lymphatic spread in cervical cancer follows a sequential order, with the obturator lymph nodes being the most frequently involved (18.8%), acting as sentinel lymph nodes in many cases 2
• The external iliac lymph nodes are another primary site of metastasis, with 43% of solitary lymph node metastases occurring in this region 3
• Parametrial lymph nodes are also commonly involved, with 21% of solitary metastases found in this area 3, 4

Secondary Lymphatic Drainage Pathways

• Internal iliac (presacral) lymph nodes are less commonly involved, with only 1% of isolated metastases found in this region 3
• Common iliac lymph nodes may be affected in more advanced disease, with approximately 7% of solitary metastases and 2.9% of all lymph node metastases occurring in this area 3, 5
• Para-aortic lymph node involvement is rare without concurrent pelvic lymph node metastasis, occurring in only about 1% of cases as isolated metastases 3, 2

Distribution Pattern Based on Disease Stage

• In early-stage cervical cancer (stages IA1-IB1):

  • The risk of nodal metastasis is <1% for stage IA1 without lymphovascular space invasion 1
  • When lymphovascular space invasion is present, the risk increases significantly, requiring pelvic lymphadenectomy 1

• In locally advanced disease (stages IB2-IVA):

  • The risk of nodal involvement increases substantially, with potential spread to common iliac and para-aortic nodes 6
  • Para-aortic lymphadenectomy should be considered for patients with larger tumors and suspected or known pelvic nodal disease 1

Sentinel Lymph Node Considerations

• The obturator, parametrial, and external iliac regions should be the primary focus when performing sentinel lymph node mapping in cervical cancer 2, 4
• The lymphatic drainage from the cervix typically follows the uterine vessels through the parametria to the pelvic sidewall lymph nodes 1
• When cervical dye injection is performed for sentinel node mapping, the most common location of pelvic sentinel lymph nodes is medial to the external iliac, ventral to the hypogastric, or in the superior part of the obturator region 6

Clinical Implications

• Understanding the pattern of lymph node metastasis is critical for surgical planning and radiation field design 7
• In 62% of patients, standard radiation fields may insufficiently cover the common iliac lymph nodes, highlighting the importance of individualized treatment planning based on imaging 7
• The presence of positive pelvic lymph nodes significantly increases the risk of para-aortic nodal involvement, which has important implications for treatment planning 2

Important Considerations

• The distal external iliac lymph nodes (between the deep circumflex iliac vein and inguinal canal) have a low rate of isolated metastasis (0.2%), suggesting that extensive dissection in this area may not be necessary in early-stage disease 5
• Para-aortic spread without pelvic node involvement is rare (1%), indicating that para-aortic lymphadenectomy may be reserved for patients with positive pelvic nodes 3, 2
• Lymphovascular space invasion and deep stromal invasion are significant risk factors for lymph node metastasis and should prompt more thorough evaluation of nodal status 2