Vulvar lymphatics as demonstrated by vital dyes and lymphangiography

Human and animal studies have demonstrated that vital dye technics can delineate vulvar lymphatic patterns, which vary from those occurring clinically because dye particles may traverse unblocked channels. Lymph blockage can change these patterns to those seen clinically. Deep pelvic nodes are seldom seen on foot lymphangiography, and the vulvar technic does not appear clinically feasible. Normal unblocked spread is over or under the mons, bilaterally into the pelvis through the obturator foramen, or the Space of Retzius. Blockage by pressure, disease or deformity changes this to a clinical pattern where the lymphatic pathways approach the perianal or the deep external pudendal basins, going laterally to the thigh and then to the deep femoral nodes, here to take the "usual" pathway. Spread is invariably bilateral, with the greatest dispersion not necessarily on the homologous side.