What is a vascular nevus?

A vascular nevus is a type of tumor in the skin's vascular tissue, with varying nomenclature and classifications. Traditionally, it refers to "hemangiomas," which are now categorized into hemangiomas and vascular malformations.

The fundamental difference is that hemangiomas are vascular tumors caused by abnormal proliferation of vascular endothelial cells, while vascular malformations involve dilated vascular lumens due to developmental abnormalities in the vascular system, without abnormal endothelial cell proliferation.

Which department should I visit for a vascular nevus?

Departments: Dermatology, Plastic Surgery, Pediatrics.

What causes a vascular nevus?

Vascular nevi are mainly divided into hemangiomas and vascular malformations, with different causes for each type.

The exact cause of hemangiomas is unclear but is believed to be closely related to "angiogenesis," specifically abnormal proliferation of vascular endothelial cells.

Vascular malformations are congenital developmental abnormalities of blood or lymphatic vessels, resulting from irregularities in the "vascular formation" process during embryonic development, leading to structural vascular anomalies.

Who is most commonly affected by vascular nevi?

Different types of vascular nevi affect different populations:

• Infantile hemangiomas are the most common benign tumors in infants, with an incidence of 8%–12%. Premature and low-birth-weight infants have a higher risk, and they are more common in girls than boys.
• Hemangioendotheliomas are rare, with no significant age or gender differences.
• Most vascular malformations are congenital, with equal incidence in males and females.

What are the main manifestations of vascular nevi?

Different types present differently:

1. Infantile hemangiomas initially appear as erythematous, bruise-like, or telangiectatic patches. The early proliferative phase occurs within the first 3 months after birth, with rapid growth forming raised, strawberry-like plaques or tumors. Some may cover up to 80% of the body surface. Growth slows by 6–9 months, though some cases persist beyond 1 year.

2. Hemangioendotheliomas present as slow-growing solitary or multiple nodules or plaques on the skin or mucous membranes, often without distinctive clinical features.

3. Capillary malformations, also called port-wine stains, are present at birth, commonly on the face or neck. They appear as light or dark red irregular patches that blanch with pressure. Over time, they may darken or develop nodular lesions.

4. Venous malformations, or cavernous hemangiomas, are congenital venous abnormalities. They manifest as soft subcutaneous masses—round or irregular, nodular or lobulated—with indistinct borders and a smooth surface. The color ranges from bright red to dark purple-blue, and they are often compressible, resembling sponges.

How is a vascular nevus diagnosed?

Diagnosis relies on medical history, clinical presentation, physical examination, imaging, and pathological tests. Criteria vary by classification.

How is a vascular nevus treated?

Treatment depends on the type:

1. Infantile hemangiomas may require individualized treatment. Superficial types can be treated with β-blockers or lasers. High-risk or treatment-resistant cases may require propranolol, corticosteroids, local injections, embolization, or surgery.

2. Stable hemangioendotheliomas may only need monitoring. Limited or superficial cases can be surgically excised, while growing or symptomatic lesions may require medication.

3. Capillary malformations can be treated with lasers, photodynamic therapy, intense pulsed light, or surgery.

4. Venous malformations are primarily treated with intravascular sclerotherapy. Other options include lasers, copper needle retention, electrochemistry, or compression therapy. Surgery is reserved for necessary cases.

What is the prognosis for vascular nevi?

Prognosis varies by type:

1. Infantile hemangiomas often regress over years, but untreated cases may leave residual skin changes like scars, atrophy, hypopigmentation, telangiectasia, or skin laxity.

2. Some hemangioendotheliomas have a severe course, with poor outcomes due to coagulopathy, sepsis, or organ damage.

3. Vascular malformations grow proportionally with the patient. Early treatment of capillary malformations can achieve 80%–90% improvement and prevent psychological impacts.

What should patients with vascular nevi be aware of?

Avoid pressure, friction, or scratching to prevent ulceration and infection. Hemangioendothelioma patients should monitor blood counts to assess platelet levels and coagulation.