Klippel-Trénaunay syndrome is a rare congenital malformation with an incidence of 1 out of 27,500 live births, characterised by a triad of venous malformations or varicose veins, cutaneous capillary malformations and bony or soft-tissue hypertrophy in affected limbs. The lung, trunk, gastrointestinal tract, neurovascular structures and the bladder may be involved with the presence of vascular malformations.