Klippel-Trenaunay syndrome in a boy with concomitant ipsilateral overgrowth and undergrowth

Large birth mark and unilateral swelling of the lower extremity in a young teenager

We describe an early adolescent male who was diagnosed with vascular malformation associated with unilateral limb overgrowth based on the clinical findings of a persistent port-wine stain since birth and gradually progressing right lower limb oedema since early childhood. Clinicians should keep in mind to clinically evaluate such malformations in detail, as well as contemplate genetic testing in patients presenting with a large port-wine stain at birth, particularly if well demarcated and lateral in a lower extremity.

Klippel-Trenaunay syndrome or not? An exploration of atypical presentations

Klippel-Trenaunay syndrome (KTS) is a rare, congenital disorder typically emerging in early infancy or childhood. The classic presentation of KTS is distinguished by a triad of clinical features: a port-wine stain, early-onset varicosities and limb overgrowth. However, a notable variant of KTS has been documented, characterised by limb shortening rather than lengthening, occasionally referred to as 'inverse KTS'. This report details two cases that display this unusual presentation-both patients had classical features of port-wine stain and varicose veins but both experienced shortening of the affected limb. Whether these cases represent a variant of KTS or a new clinical syndrome altogether is uncertain. They however offer valuable insights into the nuances and breadth of clinical manifestations associated with this syndrome.

Klippel-Trenaunay Syndrome, Segmental/Focal Overgrowth Malformations: A Review

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.

Segmental undergrowth is associated with pathogenic variants in vascular malformation genes: A retrospective case-series study

Segmental overgrowth has been widely described in patients with congenital vascular anomalies. However, segmental undergrowth has been poorly characterized, and no large series of patients have been published. We present the clinical and molecular characteristics a cohort of 37 patients with vascular malformations and segmental undergrowth. True undergrowth was only considered when the musculoskeletal system was involved to avoid confusion with other causes of segmental reduction, as in lipodystrophy or the long-term osteopenia seen in patients with Servelle-Martorell syndrome. Deep high-throughput sequencing was performed in tissue samples from 20 patients using a custom panel. We identified three groups: undergrowth associated with (1) venous, (2) capillary-venous, and (3) lymphatic-capillary-venous malformations. Congenital or early childhood onset undergrowth can occur with or without associated overgrowth. Different likely pathogenic or pathogenic variants were detected in 13 of 20 (65%) tissue samples in the PIK3CA, TEK, GNAQ, or GNA11 genes. In conclusion, the eponymous Servelle-Martorell syndrome should not be used as a synonym for undergrowth. Segmental undergrowth should be considered a characteristic associated with vascular malformations. Patients with PIK3CA variants show all different combinations of overgrowth and undergrowth. Thus, the term PROS (PIK3CA-related overgrowth spectrum) does not cover the entire spectrum.

INVERSE KLIPPEL-TRENAUNAY SYNDROME

Objective:

To report a rare case of inverse Kipplel-Trenaunay.

Case description:

A 16-year-old girl with a grayish-depressed plaque on her left thigh. Angioresonance showed a vascular malformation affecting the skin and subcutaneous tissue.

Comments:

Inverse Klippel-Trenaunay is a Klippel-Trenaunay syndrome variation in which there are capillary and venous malformations associated to hypotrophy or shortening of the affected limb. Modifications on the limb’s length or width result from alterations in bones, muscles, or subcutaneous tissues. It has few described cases. Further clinical and molecular studies must be performed for a proper understanding.

Clinical and genetic evaluation of six children with diffuse capillary malformation and undergrowth

BACKGROUND

Diffuse capillary malformation with overgrowth (DCMO) has been well described. However, capillary malformation with undergrowth (CMU) has been less reported in the literature.

OBJECTIVES

We sought to describe the clinical features and determine associated somatic mutations in patients with CMU.

METHODS

We searched our multidisciplinary vascular anomalies clinic database for patients with CMU. Girth and length limb measurements were performed. In case of discrepancies in length, long leg radiograph studies were obtained. Whole-exome sequencing of blood and involved tissue DNA was carried out.

RESULTS

We included six patients with CM and soft-tissue and bone undergrowth. CMs were patchy, reticulated, segmental, poorly demarcated, pink-red stains affecting the lower limb (five patients) or the whole hemibody (one patient). In five patients, the stain was diffuse, affecting more than one anatomic region. Prominent superficial veins were observed in three patients. Five patients presented with lower limb girth discrepancy; in three of them, there was also lower limb length discrepancy. In the remaining patient, only lower limb length discrepancy was found. Whole-exome sequencing from DNA tissue/blood detected previously described pathogenic somatic mutations on DDR2 (c.314G > A; p.Arg105His), GRHL2 (c.791A > G; p.Glu264Gly), and PIK3CA (c.2740G > A; p.Gly914Arg) genes.

CONCLUSION

We propose the term "diffuse capillary malformation with undergrowth" for extensive reticular CMs associated with proportionate undergrowth. All our patients had a favorable outcome, and no genotype-phenotype association was found.

Magnetic Resonance (MR) Imaging of Vascular Malformations

Vascular malformations pose a diagnostic and therapeutic challenge due to the broad differential diagnosis as well as common utilization of inadequate or inaccurate classification systems among healthcare providers. Therapeutic approaches to these lesions vary based on the type, size, and extent of the vascular anomaly, necessitating accurate diagnosis and classification. Magnetic resonance (MR) imaging (MRI) is an effective modality for classifying vascular anomalies due to its ability to delineate the extent and anatomic relationship of the malformation to adjacent structures. In addition to anatomical mapping, the complete evaluation of vascular anomalies includes hemodynamic characterization. Dynamic time-resolved contrast-enhanced MR angiography provides information regarding hemodynamics of vascular anomalies, differentiating high- and low-flow vascular malformations. Radiologists must identify the MRI features of vascular malformations for better diagnosis and classification.

Combined capillary-venous-lymphatic malformations without overgrowth in patients with Klippel-Trénaunay syndrome

OBJECTIVE

Klippel-Trénaunay syndrome (KTS) is described in the literature as a complex syndrome characterized by various combinations of capillary, venous, and lymphatic malformations associated with limb overgrowth. In the first description by Maurice Klippel and Paul Trénaunay, tridimensional bone hypertrophy was believed to be the cause of limb enlargement. The purpose of this study was primarily to assess the presence of real bone hypertrophy as a cause of enlargement of the limb and to underline the rare presence of undergrowth of the affected limb in patients with KTS.

METHODS

A two-center retrospective review including 17 KTS patients with various combinations of capillary, venous, and lymphatic malformation affecting the lower limb was performed. Differences in limb dimension were evaluated clinically. Width and length discrepancy of the affected limb was measured with radiologic imaging.

RESULTS

We found an increase of length in the affected limb in 80% of the patients. The leg length discrepancy varied from 0.2 to 2.6 cm. The median leg length discrepancy was found to be 1.4 cm. Three patients had a reduced length of the affected limb. Girth enlargement of the affected extremity was noticed in 60% of the patients, and 2 of 17 patients had hypotrophy of the involved limb. Hypertrophy (an increase in both length and width) of the bone was found in none of our cases, and the circumferential enlargement of the affected extremity was related only to soft tissue enlargement.

CONCLUSIONS

In the literature, KTS is considered the prototype of overgrowth syndromes associated with complex vascular malformations. The majority of our patients showed limb length increase associated with soft tissue enlargement without an increase of bone width; there were also two patients with limb undergrowth. A real bone overgrowth (an increase in both length and width) was not present in our patients. Therefore, we could consider the absence of real bone hypertrophy as probably a new aspect of such confusing and controversial definitions of KTS. In addition, it would be more accurate to classify KTS patients on the basis of their phenotypic features (type of vascular malformation, types of overgrown tissue) rather than by use of an outdated eponym.

Copy number variants in a population-based investigation of Klippel-Trenaunay syndrome

Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disorder that is thought to occur sporadically; however, reports of familial occurrence suggest a genetic component. We examined KTS cases to identify novel, potentially causal copy number variants (CNVs). We identified 17 KTS cases from all live-births occurring in New York (1998-2010). Extracted DNA was genotyped using Illumina microarrays and CNVs were called using PennCNV software. CNVs selected for follow-up had ≥10 single nucleotide polymorphisms (SNPs) and minimal overlap with in-house controls or controls from the Database of Genomic Variants. We identified 15 candidate CNVs in seven cases; among them a deletion in two cases within transcripts of HDAC9, a histone deacetylase essential for angiogenic sprouting of endothelial cells. One of them also had a duplication upstream of SALL3, a transcription factor essential for embryonic development that inhibits DNMT3A, a DNA methyltransferase responsible for embryonic de novo DNA methylation. Another case had a duplication spanning ING5, a histone acetylation regulator active during embryogenesis. We identified rare genetic variants related to chromatin modification which may have a key role in regulating vascular development during embryogenesis. Further investigation of their implications in the pathogenesis of KTS is warranted. © 2016 Wiley Periodicals, Inc.

Mosaic Neurocutaneous Disorders and Their Causes

Neurocutaneous disorders are a heterogeneous group of conditions (mainly) affecting the skin [with pigmentary/vascular abnormalities and/or cutaneous tumours] and the central and peripheral nervous system [with congenital abnormalities and/or tumours]. In a number of such disorders, the skin abnormalities can assume a mosaic patterning (usually arranged in archetypical patterns). Alternating segments of affected and unaffected skin or segmentally arranged patterns of abnormal skin often mirror similar phenomena occurring in extra-cutaneous organs/tissues [eg, eye, bone, heart/vessels, lung, kidney and gut]. In some neurocutaneous syndromes the abnormal mosaic patterning involve mainly the skin and the nervous system configuring a (true) mosaic neurocutaneous disorder; or an ordinary trait of a neurocutaneous disorder is sometimes superimposed by a pronounced linear or otherwise segmental involvement; or, lastly, a neurocutaneous disorder can occur solely in a mosaic pattern. Recently, the molecular genetic and cellular bases of an increasing number of neurocutaneous disorders have been unravelled, shedding light on the interplays between common intra- and extra-neuronal signalling pathways encompassing receptor-protein and protein-to-protein cascades (eg, RAS, MAPK, mTOR, PI3K/AKT and GNAQ pathways), which are often responsible of the mosaic distribution of cutaneous and extra-cutaneous features. In this article we will focus on the well known, and less defined mosaic neurocutaneous phenotypes and their related molecular/genetic bases, including the mosaic neurofibromatoses and their related forms (ie, spinal neurofibromatosis and schwannomatosis); Legius syndrome; segmental arrangements in tuberous sclerosis; Sturge-Weber and Klippel-Trenaunay syndromes; microcephaly/megalencephaly-capillary malformation; blue rubber bleb nevus syndrome; Wyburn-Mason syndrome; mixed vascular nevus syndrome; PHACE syndrome; Incontinentia pigmenti; pigmentary mosaicism of the Ito type; neurocutaneous melanosis; cutis tricolor; speckled lentiginous syndrome; epidermal nevus syndromes; Becker's nevus syndrome; phacomatosis pigmentovascularis and pigmentokeratotica; Proteus syndrome; and encephalocraniocutaneous lipomatosis.

Unilateral cataract and vitreoretinopathy in a case with klippel-trenaunay syndrome

Purpose. We present a case with Klippel-Trenaunay (KT) syndrome that had unilateral mature cataract and vitreoretinopathy. Case Report. A 17-year-old boy with KT syndrome presented to the clinic of ophthalmology for low vision in the right eye. His best corrected visual acuity (BCVA) was hand motion in the right eye and 20/20 in the left eye. Anterior segment examination revealed mature cataract in the right. During the physical examination, port-wine stains were noted over right side of his face, ankle, and toes. He had asymmetric face and his head was larger on the right side. Leg lengths were symmetrical, although he had skin hypertrophy. Cranial magnetic resonance imaging studies showed cortical atrophy discordant to his age, asymmetric vascular dilatations in the right hemisphere, hypertrophy in the right periorbital soft tissue, and choroidal plexus. The patient received an uncomplicated cataract surgery. His BCVA in the right eye improved to 20/200 after the surgery. After removing cataractous lens, we were able to examine the fundus that revealed severe vitreoretinopathy and choroidal hemangioma. Conclusion. This case emphasizes the importance of prompt ophthalmic examination in patients with KT syndrome.