From the Guidelines
Prominent external iliac chain nodes should be evaluated and managed based on the underlying cause, with consideration of infection, inflammation, or malignancy, and treatment should be tailored accordingly, prioritizing morbidity, mortality, and quality of life as the primary outcomes. When identified on imaging studies such as CT scans or MRI, prominent external iliac nodes warrant further investigation to determine their cause. Normal nodes are typically less than 1 cm in short-axis diameter; nodes larger than this threshold may be considered abnormal 1. Evaluation should include a thorough clinical examination focusing on potential primary sites of infection or malignancy, laboratory tests including complete blood count and inflammatory markers, and possibly biopsy if malignancy is suspected. Management depends on the underlying cause - antibiotics for infection, anti-inflammatory medications for inflammatory conditions, or appropriate oncologic treatment for malignancy, such as concurrent chemoradiotherapy or radiation therapy alone, which can be considered as potentially curative therapy for medically inoperable patients or for local palliation in patients with metastatic disease 1. The external iliac nodes are important because they receive lymphatic drainage from the lower extremities, external genitalia, lower abdominal wall, and pelvic organs, making them sentinel nodes for detecting pathology in these regions. In the context of bladder cancer, the treatment field should include whole bladder and all sites of gross disease plus or minus uninvolved regional lymph nodes, including the hypogastric, obturator, internal and external iliac, perivesical, sacral, and presacral nodes 1. For patients with stage IIIA disease, neoadjuvant cisplatin-based chemotherapy followed by radical cystectomy and pelvic lymphadenectomy is recommended, and adjuvant radiation therapy may be considered based on pathologic risk 1. Persistent enlargement without clear cause should never be ignored as it may represent early metastatic disease requiring prompt intervention. In terms of radiation therapy, the volume of external-beam radiation therapy (EBRT) should cover the gross disease, parametria, uterosacral ligaments, sufficient vaginal margin from the gross disease, presacral nodes, and other nodal volumes at risk, with consideration of concurrent cisplatin-based chemotherapy 1.
From the Research
Prominent External Iliac Chain Nodes
- The external iliac lymph nodes are constant formations, with the largest being the lymph nodes of the lacuna, which are nodes of the I step for the lower extremity lymph vessels 2.
- Involvement of the next tier external iliac and obturator lymph nodes in the pelvis is common in cases of palpable metastatic melanoma confined to the groin 3.
- The deep circumflex iliac vein can be used as a landmark for the caudal limit of external iliac lymphadenectomy for early cervical cancer 4.
- The size and number of external iliac lymph nodes can vary between individuals, with a study finding that the total amount of iliac lymph nodes prevails in men, while their size is greater in women 2.
- Dual-energy computed tomography (DECT) can be used to quantify the maximum long and short axes of the external iliac lymph nodes, which may be a useful diagnostic tool for periprosthetic joint infection (PJI) 5.
Characteristics of External Iliac Lymph Nodes
- The external iliac lymph nodes are located in the pelvis and play a crucial role in the lymphatic drainage of the lower extremities and pelvic organs 2.
- The nodes can be involved in various diseases, including melanoma, cervical cancer, and periprosthetic joint infection 3, 4, 5.
- The size and shape of the external iliac lymph nodes can be measured using imaging techniques such as DECT, which may aid in the diagnosis of certain conditions 5.
Clinical Significance of External Iliac Lymph Nodes
- Involvement of the external iliac lymph nodes can be an indicator of disease spread or progression in certain cancers, such as melanoma and cervical cancer 3, 4.
- The external iliac lymph nodes can also be involved in the diagnosis and management of periprosthetic joint infection (PJI) 5.
- Accurate diagnosis and treatment of diseases involving the external iliac lymph nodes are crucial to prevent further complications and improve patient outcomes 3, 4, 5.