A 34-year-old male patient was referred with a recalcitrant leg ulcer overlying an extensive vascular malformation, which had led several times to septic soft tissue infections. During his infancy he had been diagnosed to have Klippel-Trenaunay syndrome. Clinical examination revealed asymmetric hypertrophy of the lower extremities, an extensive portwine stain on the more severely affected left limb as well as prominent venous varicosities of both legs. Hands and feet showed striking cerebriform palmoplantar hypertrophy, and macrodactily with syndactily of several fingers. All toes had been amputated in early childhood due to extreme overgrowth and currently the patient walked on his forefeet in a prominent pes equinus deformity. Further symptoms consisted in several lipomas at both arms, another portwine stain at the left hemithorax and a single café-au-lait spot at the left scapula. Angio-magnetic resonance imaging scans of both legs showed an extensive venous-lymphatic vascular malformation involving the whole subcutis and infiltrating the muscle. The chronic wound was interpreted as venous stasis ulceration. Local percutaneous sclerotherapy of the dilated veins underneath the ulcer was discussed, but considered to carry a relevant risk of skin necrosis with consecutive progression of the wound. A conventional split-skin graft led to complete wound healing. Since, the patient consequently wears custom-made compression stockings and remained free from recurrences. The syndromatic constellation of palmoplantar overgrowth, multiple lipomas, giant fingers and toes, limb overgrowth, venous-lymphatic malformation and a café-au-lait spot led to the diagnosis of Proteus syndrome. The possible aetiology, clinical manifestations, differential diagnosis and management of this rare disorder are discussed.