Mnemonic

Superficial Inguinal Node Drainage

A memory aid for the territory drained by the superficial inguinal nodes.

Expansion

Lower limb, buttock, abdominal wall below the umbilicus, perineum, anal canal below the pectinate line and scrotal skin

Expansion

The superficial inguinal nodes drain:

  • Lower limb - the whole of it
  • Buttock and lower back
  • Anterior abdominal wall below the umbilicus
  • Perineum, including scrotal and vulval skin
  • Anal canal below the pectinate line
  • Lower vagina

They do not drain:

  • The testis - para-aortic nodes, reflecting its abdominal origin
  • The glans penis - deep inguinal nodes
  • The anal canal above the pectinate line - internal iliac nodes

The horizontal group lies along the inguinal ligament and drains the trunk and perineum; the vertical group lies along the great saphenous vein and drains the limb.

Palpable inguinal nodes are common and often reactive from minor foot lesions, so significance depends on size, consistency and the search for a primary within the territories above.