Intraneural hemangioma in Klippel–Trenaunay syndrome: role of musculo-skeletal ultrasound in diagnosis—case report and review of the literature

Klippel–Trenaunay syndrome (KTS) is a rare congenital disorder with an incidence of 1 in 100,000. It is characterized by a triad of capillary malformations (hemangiomas) or port-wine stains, venous varicosities, and bony- or soft-tissue hypertrophy. The capillary malformation is usually confined to a single extremity, usually a lower limb. The disease can lead to various morbidities, such as bleeding, deep vein thrombosis, venous ulcers, and embolic complications. We report a case of an 11-year-old girl who presented with the three classical symptoms of KTS, with port-wine stains in the left leg, an enlarged and elongated left leg, and soft-tissue hypertrophy and multiple venous varicosities in the left tibia. A subcutaneous hemangioma along with intramuscular hemangiomas in the leg muscles was noted with increased adipose tissue. The rare finding of an intraneural hemangioma of the distal posterior tibial nerve was also diagnosed. Ultrasound of the lower limb was the main tool in making the diagnosis of KTS. X-Ray and MRI were ancillary imaging modalities. This article describes the case study of the child and the findings of a detailed ultrasound examination.