Which lymph nodes are commonly involved in uterine sarcoma?

Commonly Involved Lymph Nodes in Uterine Sarcoma

In uterine sarcoma, lymph node involvement is uncommon, and routine lymphadenectomy is not recommended as part of standard surgical management. 1

Lymphatic Drainage Patterns in Uterine Sarcoma

Unlike endometrial carcinoma, uterine sarcomas rarely metastasize to lymph nodes. The lymphatic spread pattern differs based on the specific type of uterine sarcoma:

By Sarcoma Subtype:

• Leiomyosarcoma: Lymph node metastasis is rare; lymphadenectomy is not indicated 2
• Undifferentiated endometrial sarcoma: Lymphadenectomy not routinely indicated 2
• Low-grade endometrial stromal sarcoma: Recent data suggests higher nodal involvement than previously thought; lymphadenectomy may be considered 2
• Carcinosarcoma: Requires lymph node assessment as part of comprehensive surgical staging 2

When Lymph Node Involvement Does Occur:

When uterine sarcomas do spread to lymph nodes, they typically follow these patterns:

1. Pelvic lymph nodes:

   • External iliac nodes
   • Internal iliac (hypogastric) nodes
   • Obturator nodes
   • Common iliac nodes

2. Para-aortic lymph nodes:

   • Inframesenteric region
   • Infrarenal region

Surgical Approach to Lymph Node Assessment

The NCCN guidelines clearly state that "lymphadenectomy is not recommended for patients with uterine sarcoma because metastasis to the nodes is unusual." 1

However, in specific circumstances:

• Excision of suspicious or enlarged lymph nodes should be performed regardless of sarcoma type 1
• For carcinosarcoma (now classified as a metaplastic carcinoma), lymph node assessment is indicated as part of comprehensive surgical staging 2

Clinical Implications

• Standard surgical approach: Total abdominal hysterectomy and bilateral salpingo-oophorectomy without routine lymphadenectomy 2, 3
• Selective lymphadenectomy: Only indicated in cases with:
  • Extrauterine disease
  • Suspicious or enlarged lymph nodes
  • Carcinosarcoma histology
  • Possibly in low-grade endometrial stromal sarcoma based on newer evidence 2

Important Considerations

• Preoperative imaging cannot reliably identify lymph node metastasis in uterine sarcoma 4
• The rarity of uterine sarcomas has limited the development of strong evidence-based guidelines specific to lymph node management 3
• Treatment decisions should be made in multidisciplinary sarcoma reference centers 4

Understanding the uncommon nature of lymphatic spread in uterine sarcoma helps avoid unnecessary lymphadenectomy and its associated morbidity while ensuring appropriate surgical management for these aggressive tumors.