Klippel-Trenaunay syndrome is an uncommon, infrequent, congenital disorder characterized by a triad of capillary malformation, varicosities, and tissue and bone hypertrophy. The presence of two of these three signs is enough to obtain the diagnosis. Capillary malformations are usually present at birth, whereas venous varicosities and limb hypertrophy become more evident later. The syndrome has usually a benign course, but serious complications involving various organs, such as gastrointestinal and genitourinary organs, as well as the central nervous system, may be observed. Recently, Klippel-Trenaunay syndrome has been included in the group of PIK3CA-related overgrowth spectrum (PROS) disorders. In terms of this disorder, new results in etiopathogenesis and in modalities of treatment have been advanced. We report here a review of the recent genetic findings, the main clinical characteristics and related severe complications, differential diagnoses with a similar disorder, and the management of patients with this complex and uncommon syndrome.

BACKGROUND: Klippel-Trenaunay syndrome (KTS) is a rare congenital syndrome characterized by the triad of venous varicosities, capillary malformations and limb hypertrophy. However, KTS may rarely occur in combination with kyphoscoliosis.
METHODS: We presented an 18-year-old female with KTS and kyphoscoliosis. Hypertrophy of bone and soft tissue affected her left face, trunk and lower limb. Moreover, the patient is associated with subacute thyroiditis, vitamin D deficiency and iron deficiency anemia, high level of D-dimer, swollen tonsil, kyphoscoliosis and Chiari-I-malformation without syringomyelia. A posterior correction and spinal fusion from T10 to L5 levels were performed for this patient. The lumbar curve was corrected from 105° to 60° and the kyphosis improved from 58° to 26°. The distance of trunk shift decreased from 10 cm to 1.4 cm. There were no thrombotic events occurred. At the 8th month follow-up, there was no significantly change of the curve in the coronal and sagittal radiographs. During the 31-month follow-up, the patient did not experience any discomfort. And her general appearance did not have any change until the last follow-up. However, she refused to take radiograph for worrying about radiation.
CONCLUSIONS: KTS is a rare disease with classic clinical triad. However, it can also have other different features, including kyphoscoliosis, elevated D-Dimer, vitamin D deficiency and iron-deficiency anemia. These issues should be taken into consideration when planning treatment for kyphoscoliosis in KTS patients.