High-yield overview
Low-Flow Combined Vascular Malformation with Limb Overgrowth
Low-flow CLVMCapillary-lymphatic-venous malformation - no arteriovenous shunt
PIK3CA mosaicSomatic activating mutation; 19/21 KTS in the Luks series
Triad in 63%Capillary stain 98%, varicosities 72%, hypertrophy 67% (Mayo, n=252)
LLD in 84%Of KTS patients referred to orthopaedics; half need surgery
What defines it
Vascular lesion
PatternA LOW-FLOW combined capillary-lymphatic-venous malformation (ISSVA: 'combined vascular malformation', Klippel-Trénaunay syndrome = CLVM + limb overgrowth) - NOT an arteriovenous malformation; no significant arteriovenous shunting.
Treatment
Clinical triad
PatternCapillary malformation (port-wine stain), atypical varicosities / venous malformation (characteristically a LATERAL embryonic vein), and bony and/or soft-tissue LIMB OVERGROWTH, usually of one lower limb.
Treatment
Genetics
PatternSporadic; somatic MOSAIC activating mutations of PIK3CA (PI3K/AKT/mTOR pathway) in affected tissue - within the PIK3CA-related overgrowth spectrum (PROS). Not inherited.
Treatment
What it is not
PatternParkes-Weber syndrome: capillary malformation + overgrowth WITH a high-flow arteriovenous malformation/fistulae - bruit, thrill, warmth, risk of high-output cardiac failure.
Treatment
Critical Must-Knows
- KLIPPEL-TRÉNAUNAY(-WEBER) SYNDROME is a sporadic, congenital, low-flow combined capillary-lymphatic-venous malformation (CLVM) with limb overgrowth. In the ISSVA classification it sits under 'combined' vascular malformations; Klippel-Trénaunay syndrome is defined as CLVM + limb overgrowth. The classic triad is a capillary malformation (port-wine stain), atypical varicosities or venous malformation and limb overgrowth (usually one lower limb). In the Mayo series of 252 patients, capillary malformation was present in 98%, varicosities/venous malformation in 72% and hypertrophy in 67%; the full triad in 63%.
- The cause is a somatic MOSAIC activating mutation of PIK3CA in the malformed tissue (Luks: 19 of 21 KTS patients were somatic mosaic; five mutations accounted for ~80% of cases, and many specimens contained fewer than 10% mutant cells) - so it is not inherited, does not run in families, and belongs to the PIK3CA-related overgrowth spectrum (PROS) together with CLOVES and related disorders.
- The lateral marginal vein of Servelle - a persistent embryonic lateral leg vein - is characteristic, reported in fewer than 20% of patients, and matters because it drives venous hypertension and potentially lethal thromboembolism. Before any varicosity is ablated or stripped, the deep venous system must be confirmed on imaging, because it may be absent or hypoplastic.
- COMPLICATIONS include localised intravascular coagulopathy (LIC) - raised D-dimer, phleboliths, episodic pain, and in severe LIC a falling fibrinogen with bleeding risk; venous thromboembolism (DVT and pulmonary embolism, especially peri-procedural); bleeding from varicosities or visceral involvement (rectal bleeding, haematuria); cellulitis; and orthopaedic sequelae - limb-length discrepancy, macrodactyly, angular deformity, scoliosis and gait disturbance.
- ORTHOPAEDIC workload is real: of 410 Mayo KTS patients, 64% required orthopaedic evaluation; of those, 84% had limb-length discrepancy, and half underwent surgery, most commonly (62%) for limb-length discrepancy. The clearest surgical indication is a projected limb-length discrepancy exceeding ~2 cm at skeletal maturity, treated with epiphysiodesis in the growing child.
- MANAGEMENT is conservative first: graded compression garments are the hallmark, with surveillance. Symptomatic venous elements are treated by sclerotherapy, endovenous thermal ablation or surgery (including ablation of a significant lateral marginal vein to reduce thromboembolic risk); sirolimus (mTOR inhibitor) has phase-II evidence in complicated vascular anomalies, and alpelisib (PI3K inhibitor) is licensed for PROS from age two years. Peri-procedural thromboprophylaxis is essential.
Clinical Pearls
- “KTW = low-flow combined CLVM + limb overgrowth; NOT an AVM, NOT inherited (somatic mosaic PIK3CA, PROS).
- “Triad: port-wine stain (98%), atypical/lateral varicosities (72%), limb overgrowth (67%); full triad 63% (Mayo 252).
- “Lateral marginal vein of Servelle (<20%) - venous hypertension + thromboembolism; confirm the deep system before any venous intervention.
- “LIC: raised D-dimer + phleboliths + pain; severe LIC = low fibrinogen = bleeding risk; LMWH treats the pain.
- “Orthopaedics: 84% of referred patients have LLD; epiphysiodesis when projected discrepancy exceeds ~2 cm.
- “Parkes-Weber = high-flow AVM (bruit, thrill, warmth, high-output failure) - the critical distinction.
Low-Flow Malformation, Not an Arteriovenous Malformation
The triad and the vein
Capillary malformation + atypical (lateral) varicosities + limb overgrowth. The lateral marginal vein of Servelle is characteristic. No bruit, no thrill, no warmth, no high-output cardiac failure.
Do not call it Parkes-Weber
Parkes-Weber adds a high-flow arteriovenous malformation to capillary staining and overgrowth. Confusing the two leads to wrong imaging, wrong management and missed cardiac risk. KTW is low-flow.
Overview, Terminology & Epidemiology
Klippel-Trénaunay syndrome (often written Klippel-Trénaunay-Weber, acknowledging Weber's later descriptions of limb hypertrophy with vascular malformation) is a congenital, sporadic, low-flow combined vascular malformation with limb overgrowth. The defining lesion is a combined capillary-lymphatic-venous malformation (CLVM); under the International Society for the Study of Vascular Anomalies (ISSVA) classification, Klippel-Trénaunay syndrome is the eponym for CLVM with limb overgrowth - a 'combined' vascular malformation, not a vascular tumour and not an arteriovenous malformation (Wassef 2015).
- How rare: it is sporadic and uncommon; a frequently quoted estimate is an incidence of about 1 in 100,000 (from the recent case-report literature), with no sex or ancestral predilection and no familial recurrence, consistent with a post-zygotic mosaic mechanism.
- The eponym problem: much of the older literature mixed Klippel-Trénaunay syndrome with other overgrowth and high-flow conditions; modern series therefore use strict criteria (low-flow CLVM plus overgrowth), and some authors argue patients should be classified by their phenotype (malformation components, tissue overgrown) rather than by the eponym at all (Brandigi 2018). For the clinician, the safe habit is to state the malformation type and the ISSVA category, then add the eponym.
- Historical anchor: Klippel and Trénaunay described the 'naevus variqueux ostéo-hypertrophique' in 1900; Parkes Weber reported limb hypertrophy with vascular malformation in 1907 and described the high-flow arteriovenous variant in 1918 - the reason the two eponyms must not be fused (see References; these predate MEDLINE and carry no PMID).
Genetics & Pathophysiology: PIK3CA Mosaicism
A Somatic Mosaic Overgrowth Disorder
Klippel-Trénaunay syndrome is caused by somatic (post-zygotic) activating mutations of PIK3CA - the catalytic subunit of phosphoinositide 3-kinase - within the malformed tissue. The mutation activates the PI3K/AKT/mTOR growth and angiogenesis pathway in a mosaic patch, producing a segmental lesion: a combined capillary-lymphatic-venous malformation with overgrowth of the affected limb. Because the mutation is mosaic, the condition is sporadic, not inherited, and detection requires sampling of affected tissue with deep-sequencing techniques able to find low-level mosaicism (Luks 2015; Mirzaa, GeneReviews).
- The Luks series (2015): of 21 patients with Klippel-Trénaunay syndrome, 19 (90%) were somatic mosaic for PIK3CA mutations; across isolated lymphatic malformations and the PIK3CA-overgrowth disorders, five specific PIK3CA mutations accounted for about 80% of cases, and many affected-tissue specimens contained fewer than 10% mutant cells - which is why blood testing is often negative and tissue sampling with sensitive assays is required.
- PIK3CA-related overgrowth spectrum (PROS): Klippel-Trénaunay syndrome sits within PROS alongside CLOVES syndrome, fibroadipose vascular anomaly and megalencephaly-capillary malformation. The shared biology has therapeutic consequences: the PI3K inhibitor alpelisib is licensed for PROS from the age of two years, and the downstream mTOR inhibitor sirolimus has prospective evidence in complicated vascular anomalies.
- Why the limb overgrows: the overgrowth tracks the malformation - predominantly soft-tissue enlargement with limb elongation; in a 17-patient series, no patient had true tridimensional bony hypertrophy, and occasional limbs were even undergrown (Brandigi 2018). Length increase is real (80% of that series) and is what generates limb-length discrepancy.
Genetics Soundbite
Q: What is the genetic basis of Klippel-Trénaunay syndrome, and why is it not inherited?
A: A somatic mosaic activating PIK3CA mutation in the affected tissue (PI3K/AKT/mTOR pathway) - post-zygotic, so sporadic and not passed on; it places KTW within the PIK3CA-related overgrowth spectrum (PROS). Detection needs affected-tissue sampling and deep sequencing because mutant cell fractions can be below 10%. The same biology underlies targeted therapy: sirolimus (mTOR) and alpelisib (PI3K).
Clinical Presentation: The Triad and Its Variants
Capillary malformation (port-wine stain)
- Frequency
- 246/252 (98%)
- Notes
- Usually on the affected limb; may be geographic; laser can lighten the stain
Varicosities / venous malformation
- Frequency
- 182/252 (72%)
- Notes
- Characteristically a LATERAL embryonic vein (lateral marginal vein of Servelle); may be present from childhood
Limb hypertrophy (bony/soft tissue)
- Frequency
- 170/252 (67%)
- Notes
- Usually one lower limb; girth increase is soft tissue; length increase drives discrepancy
Full triad present
- Frequency
- 159/252 (63%)
- Notes
- 37% had two of the three features - absence of one element does not exclude the diagnosis
Atypical veins (lateral vein, persistent sciatic vein)
- Frequency
- 182/252 (72%)
- Notes
- Embryonic remnants; relevant to thromboembolic risk and to surgical planning
- Distribution: usually one lower limb; upper-limb, bilateral and truncal involvement occur. The capillary stain may extend onto the trunk; visceral venous/lymphatic involvement can present with rectal bleeding or haematuria (Kocaman 2009).
- The lateral marginal vein of Servelle: a persistent embryonic lateral leg vein, reported in fewer than 20% of patients; it produces a lateral varicosity visible from childhood and is clinically important because of venous hypertension and potentially lethal thromboembolic events (Fereydooni & Nassiri 2020). The persistent sciatic vein is the other embryonic remnant encountered.
- Overgrowth: present at birth or emerging in early childhood, progressive through growth; girth enlargement is soft tissue; macrodactyly and toe anomalies (including ectrodactyly/syndactyly patterns) occur in the foot; limb-length discrepancy is the dominant orthopaedic problem.
- Symptoms beyond appearance: pain and episodic swelling (often thrombosis within the low-flow malformation), lymphoedema, lymphatic leakage/lymphorrhoea and vesicles, bleeding from varicosities, superficial thrombophlebitis, deep vein thrombosis, and recurrent cellulitis of the affected limb (Asghar 2020; case literature).
Klippel-Trénaunay versus Parkes-Weber: The Critical Distinction
Vascular lesion
- Klippel-Trénaunay(-Weber)
- LOW-flow combined capillary-lymphatic-venous malformation
- Parkes-Weber syndrome
- Capillary malformation PLUS high-flow arteriovenous malformation/fistulae
Flow signs
- Klippel-Trénaunay(-Weber)
- No bruit, no thrill, no abnormal warmth
- Parkes-Weber syndrome
- Bruit and thrill, warm limb, bounding pulses
Cardiac risk
- Klippel-Trénaunay(-Weber)
- None from the malformation itself
- Parkes-Weber syndrome
- High-output cardiac failure in significant shunts
Veins
- Klippel-Trénaunay(-Weber)
- Lateral marginal vein (Servelle); deep system may be anomalous
- Parkes-Weber syndrome
- Dilated draining veins from shunting
Genetics
- Klippel-Trénaunay(-Weber)
- PIK3CA mosaic (PROS)
- Parkes-Weber syndrome
- Classically RASA1-related (capillary malformation-AVM spectrum)
Management emphasis
- Klippel-Trénaunay(-Weber)
- Compression, sclerotherapy/ablation, epiphysiodesis, sirolimus
- Parkes-Weber syndrome
- AVM embolisation strategies; cardiac monitoring
Exam point
- Klippel-Trénaunay(-Weber)
- Low-flow; manage conservatively
- Parkes-Weber syndrome
- High-flow - the dangerous one
One-Line Discriminator
Both have a capillary stain and an overgrown limb. Feel and listen: Parkes-Weber is warm with a thrill and a bruit (high-flow AVM); Klippel-Trénaunay is not (low-flow CLVM). Duplex ultrasound settles it at the bedside.
Investigation & Imaging
- Diagnosis is clinical - the triad is visible; imaging characterises the malformation, excludes a high-flow shunt, maps the venous anatomy (including whether a deep venous system is present) and quantifies overgrowth.
- Duplex ultrasound is the first-line test: confirms low-flow venous/lymphatic channels (no arteriovenous shunting), maps the lateral marginal vein, and identifies thrombosis and reflux (Ochoco 2019; Bertino 2019).
- MRI (with MR venography): defines the extent and tissue planes of the capillary-lymphatic-venous malformation, the embryonic veins and deep-system patency; it is the roadmap for any intervention (Bertino 2019).
- Plain radiographs / scanogram: document limb overgrowth and limb-length discrepancy serially (scanograms or orthoradiographs for planning epiphysiodesis); phleboliths on a plain film are a low-flow-malformation signature.
- CT venography demonstrates the marginal vein and drainage where MRI is impractical.
- Blood tests: D-dimer (± fibrinogen) for localised intravascular coagulopathy; full blood count for chronic blood loss; coagulation profile before any procedure.
- Genetics: not required for the clinical diagnosis; when sought (e.g. before targeted therapy), test affected tissue with deep sequencing for low-level PIK3CA mosaicism (blood is usually negative).
Management
Compression and Surveillance Are the Treatment for Most
- Graded compression garment on the affected limb - the hallmark of conservative management; controls swelling, venous hypertension and lymphoedema (Gloviczki 2007).
- Surveillance: limb length (scanograms), spine, foot, skin/lymphatic complications, D-dimer, and psychosocial support within a multidisciplinary vascular-anomalies clinic.
- Laser therapy can lighten the capillary stain; emollients and wound care for lymphatic vesicles.
- Analgesia and LMWH for localised intravascular coagulopathy pain; early antibiotics for cellulitis.
- Most patients are managed without any operation (Mayo: the clearest indication for surgery is limb-length discrepancy projected to exceed 2 cm).
Complications: Coagulopathy, Thromboembolism, Bleeding, Infection
Evidence
Localised intravascular coagulopathy complicates large venous malformations - D-dimer is the marker
Dompmartin A, Acher A, Thibon P, et al. • Arch Dermatol (2008)
Key Findings:
- Prospective two-centre study of 140 patients with venous malformations with coagulation parameters; MRI in 110.
- 59/140 (42%) had raised D-dimer; 36 of those (61%) had levels above 1.0 microg/mL; six had low fibrinogen.
- Large surface area and palpable phleboliths were independently associated with raised D-dimer on multivariate analysis.
- Severe LIC (raised D-dimer WITH low fibrinogen) clustered in extensive venous malformations of an extremity and carries a high haemorrhage risk; low-molecular-weight heparin treats LIC pain and prevents decompensation to disseminated intravascular coagulation.
Clinical implication: Measure D-dimer (and fibrinogen when raised) in any extensive limb venous/lymphatic malformation - LIC explains episodic pain, predicts peri-procedural bleeding, and is treated with LMWH, not dismissed.
Limitation: The cohort covered venous malformations of all types rather than Klippel-Trénaunay syndrome alone, so the 42% figure is not KTW-specific; it defines the mechanism and the test, not the exact KTW prevalence.
- Mechanism: chronic consumption within stagnant low-flow channels → elevated D-dimer, phleboliths (calcified thrombi - palpable, and visible on plain radiographs), episodic pain from local thrombosis.
- Severe LIC: D-dimer raised with fibrinogen falling → risk of serious bleeding, especially with surgery or sclerotherapy; treat with low-molecular-weight heparin, which also relieves LIC pain.
- Peri-procedural: correct/anticoagulate LIC before interventions; a D-dimer belongs in the work-up of any child with an extensive limb malformation being considered for surgery.
Guidelines, Registries & Global Practice
There is no disease-specific guideline or registry for Klippel-Trénaunay syndrome. Practice is anchored by the ISSVA classification (Wassef 2015), the International Union of Phlebology consensus on venous malformations (Lee 2014 - which covers D-dimer, anticoagulation and the marginal vein within syndrome-based malformations), and large single-centre series (Mayo). Worldwide, care is delivered by multidisciplinary vascular-anomalies teams - paediatrics, dermatology, interventional radiology, vascular surgery/medicine, haematology and orthopaedics - with diagnosis clinical, first-line imaging by duplex ultrasound and MRI, conservative management by compression and surveillance, and interventions reserved for symptoms, coagulopathy and deformity. Access to compression garments, MRI and targeted drugs varies widely; the transferable core everywhere is correct classification, low-flow confirmation, coagulation assessment and limb-length surveillance.
Mnemonics & Memory Aids
Mnemonic
CLOVER
C
Capillary malformation (port-wine stain) - 98% in the Mayo series
L
Lateral marginal vein of Servelle (embryonic vein; <20%; thromboembolic risk)
O
Overgrowth of the limb (length and girth; girth is soft tissue)
V
Varicosities / venous malformation (72%) - LOW-flow, no shunt
E
Elevated D-dimer - localised intravascular coagulopathy (phleboliths, pain; LMWH)
R
RAS-free zone - PIK3CA mosaic (PROS); Parkes-Weber is the RASA1/high-flow mimic
Hook:CLOVER: Capillary stain, Lateral vein, Overgrowth, Varicosities (low-flow), Elevated D-dimer, and remember PIK3CA not RASA1 - the high-flow Parkes-Weber mimic.
Historical primary descriptions, all pre-MEDLINE so no PMID exists: Klippel M, Trénaunay P. Du naevus variqueux ostéo-hypertrophique. Archives Générales de Médecine, 1900. Weber FP. Angioma-formation in connection with hypertrophy of limbs and hemi-hypertrophy. Br J Dermatol, 1907. Weber FP. Haemangiectatic hypertrophy of limbs - congenital phlebarteriectasis and so-called congenital varicose veins. Br J Child Dis, 1918.
MCQ Practice Points
- KTW is an ISSVA combined low-flow malformation (CLVM) + limb overgrowth; no arteriovenous shunt; caused by somatic mosaic PIK3CA mutations (PROS) - sporadic, not inherited.
- Triad frequencies (Mayo, n=252): capillary malformation 98%, varicosities 72%, hypertrophy 67%; full triad 63%.
- Lateral marginal vein of Servelle (under 20%) → venous hypertension and potentially lethal thromboembolism; image the deep system before any venous procedure.
- LIC: D-dimer raised (42% in a venous-malformation cohort), phleboliths, pain; severe LIC = low fibrinogen = bleeding risk; treat with LMWH.
- Orthopaedics: LLD in 84% of referred patients; epiphysiodesis when projected discrepancy > ~2 cm; macrodactyly debulking; scoliosis surveillance.
- Parkes-Weber = the high-flow look-alike (bruit, thrill, warmth, high-output failure) - never conflate.
- Sirolimus: partial responses in a phase-II trial; alpelisib licensed for PROS from age 2.
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
Viva scenarioStandard
The Overgrown Leg with a Port-Wine Stain
Clinical prompt
“A 9-year-old girl presents with an enlarged right leg since birth, a geographic purple-red stain on the thigh, and prominent varicosities along the lateral leg. The limb is not warm and there is no bruit. What is the diagnosis, how do you classify it, and what is the key differential?”
Viva scenarioStandard
Limb-Length Discrepancy and the Malformation
Clinical prompt
“An 11-year-old boy with Klippel-Trénaunay syndrome has a 2.3 cm leg-length discrepancy (affected side longer) that is progressing. How would you assess and manage the discrepancy, and what must you check before operating?”
Exam day cheat sheet
Klippel-Trénaunay-Weber Syndrome - Exam Day Cheat Sheet
Definition & genetics
- Low-flow combined capillary-lymphatic-venous malformation + limb overgrowth (ISSVA combined malformation)
- Somatic mosaic activating PIK3CA (PI3K/AKT/mTOR); sporadic; PROS; tissue testing, not blood
- Historical: Klippel & Trénaunay 1900; Parkes Weber 1907/1918 (high-flow variant)
Clinical triad (Mayo, n=252)
- Capillary malformation 98%; varicosities/VM 72%; hypertrophy 67%; full triad 63%
- Lateral marginal vein of Servelle (<20%) - venous hypertension, thromboembolism
- Persistent sciatic vein; visceral involvement → GI bleeding, haematuria
Complications
- LIC: D-dimer raised, phleboliths, pain; severe LIC = low fibrinogen → bleeding; LMWH
- VTE/DVT/PE - especially peri-procedural; prophylaxis mandatory; selective IVC filter
- Cellulitis, lymphoedema, lymphorrhoea, bleeding from varicosities
Investigations
- Duplex ultrasound first: low-flow confirmation, marginal vein, thrombosis/reflux
- MRI/MR venography: extent and deep-system patency; scanogram for limb length
- D-dimer ± fibrinogen; FBC; phleboliths on plain film
Management
- Compression garment + surveillance first; laser for the stain; LMWH for LIC
- Sclerotherapy / endovenous ablation of the marginal vein; confirm deep system first
- Epiphysiodesis for projected LLD > ~2 cm; macrodactyly debulking; scoliosis surveillance
- Sirolimus (partial responses, phase II); alpelisib for PROS from age 2
Never confuse
- Parkes-Weber = high-flow AVM: warm, thrill, bruit, high-output cardiac failure
- KTW is low-flow: no bruit, no thrill, no cardiac risk from the malformation
References
- Wassef M, Blei F, Adams D, et al; ISSVA Board and Scientific Committee. Vascular Anomalies Classification: Recommendations From the International Society for the Study of Vascular Anomalies. Pediatrics. 2015;136(1):e203-14. PMID: 26055853.
- Luks VL, Kamitaki N, Vivero MP, et al. Lymphatic and other vascular malformative/overgrowth disorders are caused by somatic mutations in PIK3CA. J Pediatr. 2015;166(4):1048-54.e1-5. PMID: 25681199.
- Mirzaa G, Graham JM Jr, Keppler-Noreuil K. PIK3CA-Related Overgrowth Spectrum. GeneReviews [Internet]. Seattle: University of Washington; 2013 (updated 2023). PMID: 23946963.
- Jacob AG, Driscoll DJ, Shaughnessy WJ, Stanson AW, Clay RP, Gloviczki P. Klippel-Trénaunay syndrome: spectrum and management. Mayo Clin Proc. 1998;73(1):28-36. PMID: 9443675.
- Gloviczki P, Driscoll DJ. Klippel-Trenaunay syndrome: current management. Phlebology. 2007;22(6):291-8. PMID: 18274338.
- Schoch JJ, Nguyen H, Schoch BS, et al. Orthopaedic diagnoses in patients with Klippel-Trenaunay syndrome. J Child Orthop. 2019;13(5):457-462. PMID: 31695812.
- Brandigi E, Torino G, Messina M, et al. Combined capillary-venous-lymphatic malformations without overgrowth in patients with Klippel-Trénaunay syndrome. J Vasc Surg Venous Lymphat Disord. 2018;6(2):230-236. PMID: 29233587.
- Dompmartin A, Acher A, Thibon P, et al. Association of localized intravascular coagulopathy with venous malformations. Arch Dermatol. 2008;144(7):873-7. PMID: 18645138.
- Fereydooni A, Nassiri N. Evaluation and management of the lateral marginal vein in Klippel-Trénaunay and other PIK3CA-related overgrowth syndromes. J Vasc Surg Venous Lymphat Disord. 2020;8(3):482-493. PMID: 32089498.
- John PR. Klippel-Trenaunay Syndrome. Tech Vasc Interv Radiol. 2019;22(4):100634. PMID: 31864529.
- Bertino F, Braithwaite KA, Hawkins CM, et al. Congenital Limb Overgrowth Syndromes Associated with Vascular Anomalies. Radiographics. 2019;39(2):491-515. PMID: 30844349.
- Ochoco GETD, Enriquez CAG, Urgel RJL, Catibog JS. Multimodality imaging approach in a patient with Klippel-Trenaunay syndrome. BMJ Case Rep. 2019;12(8):e228257. PMID: 31434664.
- Adams DM, Trenor CC 3rd, Hammill AM, et al. Efficacy and Safety of Sirolimus in the Treatment of Complicated Vascular Anomalies. Pediatrics. 2016;137(2):e20153257. PMID: 26783326.
- Hammill AM, Wentzel M, Gupta A, et al. Sirolimus for the treatment of complicated vascular anomalies in children. Pediatr Blood Cancer. 2011;57(6):1018-24. PMID: 21445948.
- Lee BB, Baumgartner I, Berlien P, et al. Guideline. Diagnosis and treatment of venous malformations: consensus document of the International Union of Phlebology (IUP), updated 2013. Int Angiol. 2014 (online ahead of print). PMID: 24961611.
- Uller W, Fishman SJ, Alomari AI. Overgrowth syndromes with complex vascular anomalies. Semin Pediatr Surg. 2014;23(4):208-15. PMID: 25241100.
- Kocaman O, Alponat A, Aygün C, et al. Lower gastrointestinal bleeding, hematuria and splenic hemangiomas in Klippel-Trenaunay syndrome: a case report and literature review. Turk J Gastroenterol. 2009;20(1):62-6. PMID: 19330738.
- Asghar F, Aqeel R, Farooque U, Haq A, Taimur M. Presentation and Management of Klippel-Trenaunay Syndrome: A Review of Available Data. Cureus. 2020;12(5):e8023. PMID: 32528762.
- Sikakulya FK, Egesa WI, Kiyaka SM, Anyama P. A neonate with Klippel-Trénaunay syndrome: a case report. J Med Case Rep. 2021;15(1):447. PMID: 34488883.
- Wei SY, Liu YP, Lin DC, Tsai PS. Klippel-Trénaunay syndrome with profound abdominal lymphatic-venous malformation in a three-day-old newborn: a case report and literature review. Front Pediatr. 2024;12:1326909. PMID: 38312923.
Historical primary descriptions, pre-MEDLINE, so no PMID exists: Klippel M, Trénaunay P. Du naevus variqueux ostéo-hypertrophique. Arch Gen Med. 1900;185:641-672. Weber FP. Angioma-formation in connection with hypertrophy of limbs and hemi-hypertrophy. Br J Dermatol. 1907;19:231-235. Weber FP. Haemangiectatic hypertrophy of limbs - congenital phlebarteriectasis and so-called congenital varicose veins. Br J Child Dis. 1918;15:13.