Dermatology
Vascular Malformations
Built from Dermatology, 5th Edition

What’s inside
17 sections · 176 slides
Overview
What a vascular malformation is, and how it differs from a hemangioma
- What is a vascular malformation?
- How this deck is organized
- Vascular malformation vs infantile hemangioma
- Differences between vascular malformations and infantile hemangiomas.
- Differences between vascular malformations and infantile hemangiomas. (continued)
- This figure lines up the two courses side by side: hemangioma above, malformation below.
- The four vessel types
- How malformations combine
- Where malformations occur
- Course and outlook
- History of the field
- Most common
Pathogenesis and Genetics
How a single misplaced gene fault can wire a blood vessel wrong
- Building blood vessels before birth
- Somatic mutation: the root cause
- One gene, two ways to inherit trouble
- Different malformation types trace back to different overactive growth-signaling pathways.
- Why the genetics matter clinically
- Vascular malformations for which the molecular basis is known.
- Vascular malformations for which the molecular basis is known. (continued)
- Vascular malformations for which the molecular basis is known. (continued)
- Vascular malformations for which the molecular basis is known. (continued)
- Vascular malformations for which the molecular basis is known. (continued)
- Vascular malformations for which the molecular basis is known. (continued)
- Vascular malformations for which the molecular basis is known. (continued)
- Vascular malformations for which the molecular basis is known. (continued)
- Choosing the right investigation
- Investigative tools for vascular malformations.
- Investigative tools for vascular malformations. (continued)
- Investigative tools for vascular malformations. (continued)
- This flow chart shows how a suspected capillary malformation of the head or neck is worked up.
Nevus Simplex and Port-Wine Birthmark
The two faces of a capillary malformation — a fading mark and a lifelong one
- What counts as a capillary malformation
- Nevus simplex (“salmon patch”)
- Nevus simplex: when to worry
- A: nevus simplex on the central face in a symmetric “angel kiss” pattern — typically fades within a few years.
- A stork-bite nevus simplex on the nape, with eczema (dermatitis) that has developed inside the patch.
- Port-wine birthmark: the genetic cause
- What a port-wine birthmark looks like
- The classic facial zones
- A large port-wine birthmark covering most of the left side of an infant's face.
- A port-wine birthmark of the cheek (maxillary/V2 region) in an infant — smooth surface, bright red color.
- How a port-wine birthmark changes with age
- A facial port-wine birthmark in an adult, showing the thickening and nodularity that can develop over decades.
- A: hyperplasia and nodularity in an adult with a facial port-wine birthmark.
- Acquired, port-wine-like lesions
Capillary Malformations with Pigment Changes
When a red birthmark shares the skin with a patch of extra pigment
- Nevus anemicus mixtus
- A port-wine birthmark intermingled with a nevus anemicus (pale, blanched patches) on the shoulder.
- Phakomatosis pigmentovascularis (PPV)
- Phakomatosis pigmentovascularis type IIa (cesioflammea): a large port-wine birthmark plus widespread dermal melanocytosis.
- Another example of phakomatosis pigmentovascularis IIa, with widespread port-wine birthmarks and dermal melanocytosis.
- A, B: two more examples of phakomatosis pigmentovascularis type II, combining a port-wine birthmark with dermal melanocytosis.
- Phakomatosis pigmentovascularis (PPV).
- Phakomatosis pigmentovascularis (PPV). (continued)
- Other clues that come with a wide PWB
Sturge–Weber Syndrome
When a facial birthmark comes with brain and eye blood-vessel changes
- What Sturge–Weber syndrome is
- An infant at risk for Sturge–Weber syndrome: the port-wine birthmark covers most of the left side of the face.
- The highest-risk birthmark location
- A: the “forehead area” linked to SWS risk — upper eyelid included, bounded by a line from the outer eye corner to the ear.
- Eye involvement
- Brain involvement and seizures
- Imaging the brain in Sturge–Weber syndrome
- Treating Sturge–Weber syndrome
Capillary Malformations with Overgrowth
A family of syndromes driven by an overactive cell-growth pathway
- The PI3K/AKT growth pathway
- Diffuse capillary malformation with overgrowth (DCMO)
- A: diffuse capillary malformation with overgrowth — a widespread, blotchy birthmark on the trunk, arm, and both legs.
- Klippel–Trenaunay syndrome (KTS)
- A: a dark red-purple “geographic” birthmark on the thigh with dilated veins and limb enlargement — the higher-risk pattern.
- A–C: dark, geographic Klippel–Trenaunay birthmarks with venous and lymphatic involvement and variable overgrowth.
- Klippel–Trenaunay syndrome: complications
- CLOVES syndrome
- Megalencephaly–capillary malformation syndrome
- A widespread, blotchy capillary malformation with a sharp midline cut-off on the abdomen — the megalencephaly–CM pattern.
- CLAPO syndrome
- A: a capillary malformation on the lower lip and chin, with neck swelling from a lymphatic malformation.
- Proteus syndrome
- The cerebriform (deeply furrowed, brain-surface-like) connective tissue growth on the sole of a man with Proteus syndrome.
- Overgrowth syndromes with vascular malformations.
- Overgrowth syndromes with vascular malformations. (continued)
- Overgrowth syndromes with vascular malformations. (continued)
- Overgrowth syndromes with vascular malformations. (continued)
Cutis Marmorata Telangiectatica Congenita and Telangiectasias
A persistent marbled birthmark, and the dilated small vessels called telangiectasias
- Cutis marmorata telangiectatica congenita (CMTC)
- A, B: hypoplasia (thinner girth) of the affected limb in cutis marmorata telangiectatica congenita.
- Cutis marmorata telangiectatica congenita in a newborn, showing the broad, purple, net-like vascular pattern.
- CMTC on the arm — the net-like pattern is depressed (atrophic) near the elbow due to associated skin thinning.
- Telangiectasias: dilated small vessels
- Hereditary hemorrhagic telangiectasia (HHT)
- HHT: why screening for internal AVMs matters
- Studies recommended to screen for systemic involvement and assist in the diagnosis of hereditary hemorrhagic telangiectasia (HHT).
- Studies recommended to screen for systemic involvement and assist in the diagnosis of hereditary hemorrhagic telangiectasia (HHT). (continued)
- Ataxia–telangiectasia
- Angiokeratomas
Venous Malformations
Soft, compressible, blue channels that fill up when the limb hangs down
- What a venous malformation is
- A: distortion of the tongue and lower lip from a venous malformation, leading to an open bite.
- Cephalic (head and neck) venous malformations
- An algorithm for working up and managing venous malformations, from first clinical suspicion through imaging to treatment choice.
- Venous malformations of the trunk and limbs
- The chronic clotting problem in venous malformations
- A, B: soft, compressible, blue venous malformations on the genitalia and arm.
- A: a cluster of compressible blue-violet nodules present since birth, with a central scar.
- T2-weighted MRI of a venous malformation on the foot, showing diffuse involvement of both the skin and the muscles beneath it.
- T2-weighted MRI of a neck venous malformation — the bright (hypersignal) areas are the malformation; dark dots inside are phleboliths (small clots).
- Less common venous-type lesions
Venous Malformation Syndromes
Familial venous disease, blue rubber bleb nevus, Maffucci, and glomuvenous malformation
- Familial cutaneous and mucosal venous malformation (VMCM)
- Blue rubber bleb nevus syndrome (Bean syndrome)
- Multiple small, dark blue venous nodules scattered across the skin, several sitting on top of a larger venous malformation.
- A: small blue venous nodules on a large subcutaneous venous malformation in a girl with blue rubber bleb nevus syndrome.
- Maffucci syndrome
- A: nodular venous malformations together with enchondromas distorting the hand.
- Glomuvenous malformation (GVM)
- A large, plaque-type glomuvenous malformation on the lower leg, with the cobblestone-like surface typical of this entity.
- A, B: blue-purple cobblestone papules and plaques of glomuvenous malformation on the feet.
- Cerebral cavernous malformation and its skin marker
Lymphatic Malformations
Cysts and leaky channels in the body's fluid-drainage network
- What a lymphatic malformation is
- Primary lymphedema
- Macrocystic lymphatic malformation (“cystic hygroma”)
- A: a macrocystic lymphatic malformation on the side of the trunk, soft except for a firm, bruise-colored area of bleeding.
- Microcystic lymphatic malformation (“lymphangioma circumscriptum”)
- A: clusters of small, skin-colored lymphatic vesicles — a microcystic lymphatic malformation.
- Combined micro- and macrocystic LM: head and neck
- Combined LM: trunk, limbs, and generalized disease
- Kaposiform lymphangiomatosis (KLA)
- Gorham–Stout disease (“disappearing bone”)
- Purplish papules and plaques in Gorham–Stout disease, representing combined capillary-lymphatic malformation.
- Central conducting lymphatic anomalies (CCLAs)
- A: a neonate with well-defined, fluid-bright macrocysts of an LM on MRI.
Arteriovenous Malformations
The fast-flow type — arteries connecting straight into veins
- What an arteriovenous malformation is
- The four Schobinger stages
- A, B: dormant (stage 1) AVMs — one mimics a port-wine birthmark, the other mimics an infantile hemangioma.
- Telling an early AVM apart from a capillary malformation
- This figure summarizes typical AVM sizes, locations, and growth patterns.
- A: a slowly growing red nodule with fine vessels, present since birth — an early AVM.
- Why late-stage AVMs are so serious
Arteriovenous Malformation Syndromes
Cobb syndrome, Parkes Weber syndrome, and the CM-AVM disorders
- Cobb syndrome
- A nape birthmark resembling a salmon patch, but it was warm and darker red macules appeared over time.
- Bonnet–Dechaume–Blanc syndrome
- A: a stage 2 (expanding) mid-face AVM together with AVMs of the retina and brain in a boy with Bonnet–Dechaume–Blanc syndrome.
- Parkes Weber syndrome
- Capillary malformation–arteriovenous malformation (CM-AVM) syndrome
- Multiple pink-red (A, B) to brownish (C) macules of capillary malformation–arteriovenous malformation, caused by a RASA1 mutation.
- A, B: large and small pink patches on the thigh with pale (white) halos around their edges — CM-AVM due to a RASA1 mutation.
- PTEN hamartoma tumor syndrome (PHTS)
Pathology
What each malformation type looks like under the microscope
- Microscopic features by vessel type
- A: a thickened, nodular capillary malformation in an adult, with more numerous dilated dermal capillaries.
Differential Diagnosis
Conditions that can be mistaken for a vascular malformation
- Malformations vs vascular tumors
- Non-vascular look-alikes
- Causes of acquired cutaneous lymphangiectasia.
- Acquired cutaneous lymphangiectasia
Treatment
Lasers, sclerotherapy, surgery, and the new targeted drugs
- Treating capillary malformations
- Beyond first-line laser for capillary malformations
- Treating venous malformations
- Treating lymphatic malformations
- Treating arteriovenous malformations
- Treating combined malformations and PROS
- Genetic testing in practice
- Example of a genetic panel: additional codes. Panels vary depending on the laboratory.
- Example of a genetic panel: additional codes. Panels vary depending on the laboratory. (continued)
Summary
The essential points to take away
- Takeaways: what a vascular malformation is
- Takeaways: syndromes to recognize
- Takeaways: treatment principles
References
The chapter's own cited literature
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- Dermatology, 5th Edition (2-Volume Set)