Klippel-Trenaunay-Weber syndrome (KTWS) is a sporadic congenital syndrome in which vascular involvement is prominent and is usually diagnosed at birth (Zhu et al. 2020). This syndrome is also known as capillary-lymphatic-venous malformation (CLVM), due to the changes in these blood vessels (Zhu et al. 2020). The first case was reported in 1900 (Klippel 1900). KTWS is characterized by the classic triad of cutaneous capillary hemangiomas or port-wine stains, hypertrophy of the bone or soft tissue (usually in one lower limb), and venous malformations (mainly varicose veins) (Wang et al. 2017). KTWS mainly affects the lower extremities unilaterally (equal incidence on the right and left). In rare cases, the upper limbs, head, and neck area or bilateral involvement are seen (Sung et al. 2015). Capillary manifestations are flat, red, or purple port-wine stains and are seen in 90–100% of cases (Alwalid et al. 2018). Capillary involvement is usually the first clinical finding and is present at birth and progresses as the baby grows (Wang et al. 2017). KTWS affects men and women equally in all ethnic groups and has an estimated prevalence of 2–5 per 100,000 people (Alwalid et al. 2018). All the clinical manifestations are shown in Table 1 (Online Mendelian Inheritance in Man O 2016).