In bladder cancer, 5-year survival for T1N1 tumours is 15% but is 85% for T1N0 tumours.Īccuracy of imaging in the detection of lymph node metastases For example, the 5-year survival of women with FIGO stage IB node-positive cervical cancer has been reported as 45-55%, compared to 85-95% for stage IB node-negative tumours. Pelvic metastatic lymph node involvement alters tumour staging, treatment options and prognosis. Prognostic significance of lymph node metastases Also, surgery can radically alter lymphatic drainage, which is relevant in the assessment of nodal metastases in recurrent disease. For example, in cervical carcinoma the pelvic nodes may appear normal on imaging but retroperitoneal and supra-clavicular lymph node enlargement may be identified. However certain tumour types may skip nodal stations, giving rise to non-contiguous nodal spread. The usual pathways of lymphatic drainage for each of the pelvic organs are listed in Table 13.1. The deep inguinal nodes lie medial to the femoral vein and also drain to the external iliac chain. The superficial inguinal nodes lie immediately below the inguinal ligament and drain to the external iliac chain. The other local nodal group of relevance in pelvic cancer is the inguinal chain composed of superficial and deep subgroups. The common iliac lymph nodes drain to the left and right lateral aortic chains, which are part of the lumbar (upper retroperitoneal) nodal chain. Enlargement of this chain produces the filled-in fat sign at the pelvic brim. The middle (posterior) chain lies posterior to the common iliac vessels, between the psoas muscle and the spine. The lateral chain lies lateral to the common iliac artery. The medial chain lies between both common iliac arteries and includes nodes anterior to the sacral promontory. Common iliac lymph nodes are composed of medial, middle and lateral nodes.The latter lie in the obturator foramen but are identified in less than 10% of the population. The former accompany the median and lateral sacral vessels and may drain directly into the lumbar lymphatics. This group also includes two outlying nodal sites, the sacral nodes and the 'anatomical obturator' nodes.

Internal iliac lymph nodes accompany the internal iliac vessels and drain to the common iliac chain.

The lateral chain is drain to the middle and lateral common iliac chains.

The medial chain lies between the external iliac artery and vein. Some authorities consider this group to be part of the internal iliac nodes. These are known as the ' surgical obturator' group, since they are adjacent to the obturator vessels. Intermediate nodes lie just posterior to the external iliac vein and medial to the obturator internus. External iliac lymph nodes are composed of medial, anterior and lateral chains.Nodal metastases are most frequently identified in the pelvic sidewall chains, which are the external iliac, internal iliac and common iliac nodal groups, each named after the artery it accompanies. While meso-rectal lymph node metastases are often identified in rectal cancer, the other perivisceral nodes are only rarely seen. There are perivisceral nodes in the meso-rectal fat, parametrium, and paravesical fat. Since lymphatic tumour spread is common in pelvic malignancy, it is important to identify the anatomical location of all the pelvic nodal groups and to be aware of the usual pathway of lymphatic drainage for each organ involved.

Shotty inguinal lymph nodes