Capillary malformations / Port-wine stains
Figure 1. Port-wine stain / capillary malformation on the face of a newborn
Capillary malformations or port-wine stains (PWS) initially appear flat (Figure 1), and may thicken and appear hypertrophic during adulthood. The commonest form of vascular malformations, they usually present at birth and grow in proportion to the child.
Certain PWS may result in significant cosmetic disfigurement. Pyogenic granuloma-like lesions that lead to recurrent bleeding can also develop. Large PWS affecting the forehead or eyelids may be associated with Sturge-Weber syndrome (SWS), with cranial and ophthalmological associations. These patients require brain imaging and regular eye examinations. Seizures and developmental delay are common neurological manifestations of SWS.
PWS can be treated with lasers such as pulsed-dye laser or Nd:YAG laser. Treatments can begin within the first few months of life and require multiple sessions, usually one to two months apart. Hypertrophic PWS may require reconstructive surgery or interventional ablation.
Venous and lymphatic malformations
Figure 2. Venolymphatic malformation on the buttock and thigh of a child
Venous and lymphatic malformations appear as soft, bluish-to-purplish swellings (Figure 2). The next most common forms of vascular malformations, they usually present within the first few years of life. Although mostly asymptomatic, they can present with pain, bleeding, thrombosis and secondary infection.
Diagnosis is made on clinical, radiological (e.g. ultrasound and magnetic resonance imaging) and occasionally, histological features. Recently, an increasing number of somatic genetic mutations have been discovered in these vascular anomalies (e.g.
PIK3CA). Genetic testing may be offered in some cases to guide management.
Small, asymptomatic lesions may be left alone, while treatment is recommended for larger lesions, especially if symptomatic. Various treatment modalities are often combined for optimal results, including systemic medications such as Mammalian Target Of Rapamycin (mTOR) or
PIK3CA inhibitors, sclerotherapy, lasers and surgery.
Vascular malformations syndromes
Some vascular malformations may be associated with other abnormalities, such as tissue overgrowth, bony and visceral involvement, soft tissue tumours and epidermal nevi. These “vascular malformations syndromes” are rare but have the potential to lead to severe physical and psychosocial impairment.
Somatic mosaic mutations in
PIK3CA have been found in the
PIK3CA-related overgrowth syndromes (PROS). These include Klippel-Trenaunay syndrome (Figure 3) and CLOVES syndrome. Patients with PROS present with asymmetric limb overgrowth associated with various slow-flow vascular malformations.
Figure 3. Klippel-Trenaunay syndrome affecting a child’s right leg, with capillary malformations, veno-lymphatic malformations and limb hypertrophy
Multi-modality treatment is required for these patients, including sclerotherapy, embolisation, systemic medications such as mTOR and PIK3CA inhibitors, lasers and surgery.
Other genetic mutations that have been discovered to underlie other vascular malformation syndromes include GNAQ (Sturge-Weber syndrome), AKT1 (Proteus syndrome), RASA1 (Parkes-Weber syndrome, CM-AVM syndrome) and PTEN (Bannayan-Riley-Ruvalcaba syndrome).
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