Para-aortic lymph nodes

Nodi lymphoidei lumbales

Lymphatic & immuneLymphaticsAbdomen

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What it is

Lumbar nodes lying on the back wall of the abdomen on either side of the aorta and in front of and between the aorta and inferior vena cava, from the diaphragm down to where the aorta divides. Each node is a bean-shaped filter 5-15 mm long with a fibrous capsule, an outer cortex of B-cell follicles, a T-cell paracortex and an inner medulla. Several afferent lymphatics enter its convex surface; one or two efferents leave at the hilum.

Function

Drain the kidneys, adrenals, ovaries and testes, the posterior abdominal wall and all the lymph arriving from the pelvis and legs via the iliac nodes; their efferents form the lumbar trunks.

Size

20-30 nodes of 5-15 mm

Clinical note

Because the testes descend from the abdomen, testicular cancer spreads first to these nodes at the level of the kidneys, not to the groin.