Klippel-Trenaunay syndrome in Infant/Neonate
A capillary malformation that does not cross the midline of the body, is present at birth, or develops in early childhood. Varicose veins can be extensive, appearing not only below the knee but also in the pelvic region, often sparing the saphenous distribution. They may not be visible until the child begins to walk. Hypertrophy of one or more body parts is usually seen at birth and worsens during the first few years of life. This is due to hypertrophy of the soft tissues and sometimes bone. Lymphatic manifestations include lymphedema, lymphatic blebs, and pseudoverrucous papules. Usually one extremity (the leg more commonly than the arm) is affected. Truncal involvement may occur, and the head and neck are rarely affected. Rarely, multiple limbs may be affected.
KTS is considered a subtype of the PIK3CA-related overgrowth spectrum (PROS), which includes genetic disorders resulting in overgrowth due to mutations in the PIK3CA gene. Nevertheless, the exact etiology of KTS is not fully understood, and not all patients with this syndrome have the PIK3CA gene mutation.
Complications of KTS include thrombophlebitis, thromboembolism, and coagulopathy. Cutaneous complications include stasis dermatitis and venous stasis ulcers. Vascular malformations have been reported to occur internally as well; gastrointestinal (GI) bleeding may complicate GI tract malformations. Scoliosis may develop as a result of lower limb length discrepancy.
Q87.2 – Congenital malformation syndromes predominantly involving limbs
721105004 – Klippel Trenaunay syndrome
Differential Diagnosis & Pitfalls
- Parkes-Weber syndrome, like KTS, involves extensive vascular malformations of a limb. However, in Parkes-Weber, there are usually multiple arteriovenous malformations that can be associated with high-output cardiac failure at birth.
- Servelle-Martorell has capillary malformations associated with undergrowth of a limb.
- Idiopathic congenital hemihypertrophy
- Extremity capillary malformation without associated underlying malformations or overgrowth.
- Maffucci syndrome
- Proteus syndrome