Klippel-Trenaunay Syndrome in a Pediatric Patient: A Case Report

Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disorder defined by the triad of capillary malformation, venous or lymphatic anomalies, and soft tissue or bony hypertrophy. Pediatric presentations pose distinct challenges because clinical manifestations evolve with growth, and early phenotypes may not reliably predict long-term morbidity. In early childhood, accurate flow phenotyping and anticipatory surveillance are therefore central to management.

A 4-year-old girl presented with an extensive port-wine stain involving nearly half of the right buttock, progressive hypertrophy of the right lower limb, and superficial varicosities. Limb circumference differed by 3.5 cm at the thigh and 2.8 cm at the calf compared with the contralateral side. Doppler ultrasonography demonstrated superficial venous ectasia with preserved deep venous flow and no evidence of arteriovenous shunting. Magnetic resonance venography confirmed superficial venous malformations confined to the right lower limb without pelvic or visceral involvement. Radiographs revealed cortical thickening and bony overgrowth of the right foot, and scanogram analysis demonstrated a 1.2 cm limb-length discrepancy. Conservative management with compression therapy, orthopedic surveillance, and regular dermatologic follow-up was initiated. At 6 months, the child remained asymptomatic, functionally active, and without progression of hypertrophy.

This case illustrates the diagnostic and management considerations of KTS in early childhood, emphasizing differentiation from high-flow vascular syndromes, justification of imaging strategies, and the importance of growth-adapted surveillance and family counseling. Emerging targeted therapies may offer future options for progressive disease.

Early recognition, structured monitoring, and multidisciplinary care are essential in pediatric KTS. Conservative management is effective when paired with defined surveillance strategies and caregiver-centered education.