Introduction and objective:
Klippel–Trénaunay syndrome is a rare congenital disease consisting of vascular malformations, limb overgrowth, large varicose veins and port-wine stains. It is related to the mosaic variants of PIK3CA gene. Patients with KTS usually receive symptomatic treatment, such as orthopaedic correction of limb overgrowth or varicose vein treatment. This systematic review aims to summarise knowledge about the most common of anomalies presented by Klippel–Trénaunay patients. The literature review describes the anomalies present in Klippel–Trénaunay syndrome.

Review methods:
This review was created based on 21 papers found in PubMed and PubMedCentral databases after searching for’klippel trenaunay’ and ‘hyperthrophy/anomaly/anatomical/malformation’, published between 1978–2023, as well as on Dove Press articles from 2012.

Abbreviated description of the state of knowledge:
Limb overgrowth is a dominant symptom of KTS, appearing in 67% – 100% of patients. More often it affects lower limbs, although it can also appear in the upper limbs. Overgrowth is caused by vascular malformations which, on their own, are another symptom of KTS. Patients with KTS present malformations of deep veins (e.g. popliteal vein) or superficial veins (e g. superficial femoral vein), together with embryonal veins (e.g. persisting sciatic vein). Port-wine stains can appear to up to 98% of patients, and are located mostly on the lower limbs and/or torso.

Summary:
The variety of anomalies appearing in Klippel–Trénaunay syndrome is large and diversified. Collecting and summing-up information about anatomical anomalies of Klippel–Trénaunay syndrome can help both doctors and patients in the search for more meticulous diagnosis and treatment of the symptoms.