Klippel-Trenaunay Syndrome

Klippel-Trenaunay syndrome is a congenital disorder of limb asymmetry associated with vascular abnormalities. It is also known as nevus vasculosus osteohypertrophicus and Parkes Weber syndrome (after Frederick Parkes Weber).

Diagnosis requires 2 or more of the following three classic characteristics:

• Cutaneous vascular lesions: Port-wine stain (nevus flammeus). These are mostly capillary malformations and usually involve the affected limb. Most common manifestation (seen in 98% of patients). Unlike hemangiomas, the cutaneous vascular lesions don't evolve with time.
• Abnormal venous and lymphatic structures : Varicosities and venous malformations can be superficial, deep, or perforating.
• Enlargement of an extremity: Least common of the three abnormalities. Usually unilateral involvement of a lower extremity. Enlargement of the extremity can be caused by circumferential soft-tissue hypertrophy, bone elongation, or both. The bony and soft-tissue enlargement may be due to local hyperemia and venous stasis from the aforementioned venous abnormalities.

The images above are from a patient with left leg hypertrophy, nevi predominantly on the left foot, and varicose veins throughout the left lower extremity.

References

• Elsayes KM, Menias CO, Dillman JR, Platt JF, Willatt JM, Heiken JP. Vascular malformation and hemangiomatosis syndromes: spectrum of imaging manifestations. AJR Am J Roentgenol. 2008 May;190(5):1291-9.
• Mavili E, Ozturk M, Akcali Y, Donmez H, Yikilmaz A, Tokmak TT, Ozcan N. Direct CT venography for evaluation of the lower extremity venous anomalies of Klippel-Trenaunay Syndrome. AJR Am J Roentgenol. 2009 Jun;192(6):W311-6.