“…Embryologically, there are five regional primitive lymphatic sacs which normally develop into chains of lymph nodes [2] the paired jugular sacs lateral to the internal jugular veins, an unpaired retroperitoneal sac at the root of the mesentery, and the paired sacs adjacent to the sciatic veins. These sacs form chains of lymph nodes which drain the head, neck, arm, mesentery, hip, back, and leg, respectively.…”