Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular syndrome involving bone and soft tissue hypertrophy of the involved limb and vascular malformations of the lymphatic, capillary, and venous systems. It is often confused with Parkes-Weber syndrome (PWS). KTS is characterized by a triad of capillary malformation in the form of port wine stains, bone or limb hypertrophy, and varicose veins. The vein of Servelle, also known as the lateral marginal vein, is one of the two persisting embryonic veins of the leg, the persistent sciatic vein being the other. Truncal vascular malformation can be a complication of failure of obliteration of these veins. We present a case of a 24-year-old male of KTS who had varicose veins in his right lower limbs since five years of age and macrodactyly with a synchronous presentation of the vein of Servelle.

Klippel-Trenaunay syndrome (KTS) is a rare slow-flow combined vascular malformation with limb hypertrophy. KTS is thought to lie on the PIK3CA-related overgrowth spectrum, but reports are limited. PIK3CA encodes p110α, a catalytic subunit of phosphatidylinositol 3-kinase (PI3K) that plays an essential role in the PI3K/AKT/mammalian target of rapamycin (mTOR) signaling pathway. We aimed to demonstrate the clinical utility of targeted next-generation sequencing (NGS) in identifying PIK3CA mosaicism in archival formalin-fixed paraffin-embedded (FFPE) tissues from patients with KTS.
Participants were 9 female and 5 male patients with KTS diagnosed as capillaro-venous malformation (CVM) or capillaro-lymphatico-venous malformation (CLVM). Median age at resection was 14 years (range, 5-57 years). Median archival period before DNA extraction from FFPE tissues was 5.4 years (range, 3-7 years). NGS-based sequencing of PIK3CA achieved an amplicon mean coverage of 119,000x. PIK3CA missense mutations were found in 12 of 14 patients (85.7%; 6/8 CVM and 6/6 CLVM), with 8 patients showing the hotspot variants E542K, E545K, H1047R, and H1047L. The non-hotspot PIK3CA variants C420R, Q546K, and Q546R were identified in 4 patients. Overall, the mean variant allele frequency for identified PIK3CA variants was 6.9% (range, 1.6-17.4%). All patients with geographic capillary malformation, histopathological lymphatic malformation or macrodactyly of the foot had PIK3CA variants. No genotype-phenotype association between hotspot and non-hotspot PIK3CA variants was found. Histologically, the vessels and adipose tissues of the lesions showed phosphorylation of the proteins in the PI3K/AKT/mTOR signaling pathway, including p-AKT, p-mTOR, and p-4EBP1.
The PI3K/AKT/mTOR pathway in mesenchymal tissues was activated in patients with KTS. Amplicon-based targeted NGS could identify low-level mosaicism from low-input DNA extracted from FFPE tissues, potentially providing a diagnostic option for personalized medicine with inhibitors of the PI3K/AKT/mTOR signaling pathway.

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 congenital vascular malformation with a complicated etiology. It is sporadic and clinically rare in occurrence. The typical characteristics are capillary malformation (also known as port-wine stain), varicose veins and malformations, and bony and/or soft tissue hypertrophy with or without lymphatic malformation, which are known as the \"classic clinical triad\". Herein, a rare case of KTS characterized by crossed-bilateral limb hypertrophy accompanied by intermittent hematochezia and hematuria is reported.
METHODS: We described a 37-year-old female with KTS. She was admitted to our hospital owing to the gradual enlargement of the left lower extremity along with intermittent hematochezia and hematuria. The patient was diagnosed to have hemorrhoid bleeding by other hospitals and treated with conventional hemostatic drugs, but continued to have intermittent gastrointestinal bleeding and hematuria. Therefore, she visited our hospital to seek further treatment. During hospitalization, relevant imaging and laboratory examinations and colonoscopy were performed. In combination with the patient\'s history and relevant examinations, we considered that the patient had a complex form of KTS. We recommended a combined diagnosis and treatment from the vascular, interventional, anorectal, and other departments, although she declined any further treatment for financial reasons.
CONCLUSIONS: The clinical manifestations of KTS are extensive and diverse and chiefly include the typical triad. However, Vascular malformations of KTS can also involve several parts and systems such as digestive and urogenital systems. Therefore, the atypical manifestations and rare complications necessitate the clinician\'s attention and are not to be ignored.

Klippel-Trenaunay Syndrome (KTS) is a rare congenital capillary/venous malformation (CVM) disorder associated with deep soft-tissue swelling. A seven-year-old Caucasian male with a history of Klippel-Trenaunay Syndrome presented to the dermatology clinic for evaluation and treatment of mildly edematous right lower extremity and varicose veins with multiple, small port-wine stains and nodules. Typically, cases of KTS report large port-wine stains, where a multidisciplinary approach is the mainstay for management. However, this case involves a clinical presentation of mild KTS with atypical, small port-wine stains on the affected limb.

Phacomatosis pigmentovascularis is a rare dermal disorder attributed to the presence of various nevi. These lesions exist since birth, so the patient remains well aware of them. Various systemic involvements may be associated with the nevus, but the association of Raynaud\'s phenomenon is seldom reported. Our patient came with similar features and, on workup, no neurovascular compression was present, such as cervical rib or thoracic outlet syndrome. Therefore, he was managed conservatively and experienced improvement following the treatment. The objective of reporting this case is to highlight the association of Raynaud\'s phenomenon with such nervous lesions.

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.

We report an unusual case of unilateral limb pseudo hypertrophy in a 21-year-old lady who developed progressive enlargement of the right calf followed by thigh in association with chronic leg pain. Magnetic resonance imaging (MRI) of the affected limb confirmed enlargement of various muscles. Electromyography revealed neurogenic features consistent with S1 radiculopathy. MRI of the lumbosacral spine showed tethered cord with a lipoma infiltrating multiple sacral roots. Our case illustrates that muscular pseudo hypertrophy may follow chronic denervation as a consequence of spinal neural compressive disease. The various mechanisms postulated for this distinct condition are outlined.