Etiology and pathogenesis: KTS is generally considered a sporadic condition arising from somatic mosaic mutations that disrupt vascular and lymphatic development during embryogenesis. Recent research has linked PIK3CA mutations to a spectrum of overgrowth disorders that share features with KTS, collectively referred to as the PROS group; these findings have prompted ongoing investigations into targeted therapies.
Diagnosis:Diagnosis is based on clinical assessment of the characteristic triad and exclusion of other conditions. Imaging studies such as Doppler ultrasound, magnetic resonance imaging (MRI), or CT angiography delineate the extent of venous and lymphatic malformations and help differentiate from Parkes-Weber syndrome. Genetic testing may identify mosaic PIK3CA alterations in some cases but is not routinely required for diagnosis.
Management: Treatment is multidisciplinary and individualized. Measures include compression therapy for edema, laser therapy for capillary malformations, and interventional or surgical approaches for venous malformations (sclerotherapy or embolization) and for limb-length discrepancies or functional deformities. Lymphedema management, wound care for ulcers, and pain control are important. Monitoring for complications such as deep vein thrombosis or less commonly pulmonary embolism is advised. Emerging therapies targeting the PI3K pathway are under investigation for PROS-related overgrowth conditions.