Sinus pericranii typically present as soft palpable masses along midline skull, which may fluctuate in size depending on body positioning. Classically, these lesions are not associated with color change of the overlying skin, such as with other vascular lesions such as hemangioma.

Vascular malformation is a collective term for different disorders of the vasculature (errors in vascular development). It can be a disorder of the capillaries, arteries, veins and lymphatic vessels or a disorder of a combination of these (lesions are named based on the primary vessel that is malformed). A vascular malformation consists of a cluster of deformed vessels, due to an error in vascular development (dysmorphogenesis). However, endothelial turnover is stable in these defects. Congenital vascular malformations are always already present at birth, although they are not always visible. In contrast to vascular tumors, vascular malformations do not have a growth phase, nor an involution phase. Vascular malformations tend to grow proportionately with the child. Vascular malformations never regress, but persist throughout life.

Vascular malformations can be divided into slow-flow, fast-flow and complex-combined types.

Pyogenic granuloma, also known as lobular capillary hemangioma, is a small benign vascular tumor that primarily involves the skin (88.2%) and mucous membranes. Pyogenic granuloma appears as a red macule that grows rapidly, turns into a papule and eventually becomes pedunculated, being attached to a narrow stalk. The average diameter of these lesions is 6.5 mm. Although these lesions are small, they are often complicated by bleeding, crusting and ulceration. Microscopically, pyogenic granulomas are characterized by vascular amidst granulation tissue and chronic inflammatory infiltrate.

Pyogenic granulomas are rarely congenital. It commonly develops in infants: 42.1% develops within the first 5 years of life. This vascular tumor is twice as common in males as in females and 25% of lesions seem to be associated with trauma, an underlying cutaneous condition, pregnancy, hormonal alterations and medications. Pyogenic granulomas can also arise within a capillary malformation. Of all pyogenic granulomas, 62% is distributed on the head or neck, occurring mainly on the cheek and in the oral cavity. Lesions on the face may cause visible deformity.

Numerous treament methods have been described for pyogenic granuloma. Lesions involving the reticular dermis, may be out of the reach of pulsed-dye laser, cautery or shave excision and therefore have a recurrence rate of 43.5%. Definitive management requires full-thickness skin excision. Other options are currettage or laser therapy. Furthermore, thorough currettage and cauterization are often used for small lesions and full-thickness excision for larger lesion.

Sinus pericranii (SP) is a rare disorder characterized by a congenital (or occasionally, acquired) epicranial venous malformation of the scalp. Sinus pericranii is an abnormal communication between the intracranial and extracranial venous drainage pathways. Treatment of this condition has mainly been recommended for aesthetic reasons and prevention of hemorrhage.

There are three distinct types of lymphangioma, each with their own symptoms. They are distinguished by the depth and the size of abnormal lymph vessels, but all involve a malformation of the lymphic system. Lymphangioma circumscriptum can be found on the skin's surface, and the other two types of lymphangiomas occur deeper under the skin.

- Lymphangioma circumscriptum, a microcystic lymphatic malformation, resembles clusters of small blisters ranging in color from pink to dark red. They are benign and do not require medical treatment, although some patients may choose to have them surgically removed for cosmetic reasons.

- Cavernous lymphangiomas are generally present at birth, but may appear later in the child's life. These bulging masses occur deep under the skin, typically on the neck, tongue and lips, and vary widely in size, ranging from as small as a centimeter in diameter to several centimeters wide. In some cases, they may affect an entire extremity such as a hand or foot. Although they are usually painless, the patient may feel mild pain when pressure is exerted on the area. They come in the colors white, pink, red, blue, purple, and black; and the pain lessens the lighter the color of the bump.

- Cystic hygroma shares many commonalities with cavernous lymphangiomas, and some doctors consider them to be too similar to merit separate categories. However, cystic lymphangiomas usually have a softer consistency than cavernous lymphangiomas, and this term is typically the one that is applied to lymphangiomas that develop in fetuses. They usually appear on the neck (75%), arm pit or groin areas. They often look like swollen bulges underneath the skin.

Lymphangiomas have traditionally been classified into three subtypes: "capillary" and "cavernous lymphangiomas" and cystic hygroma. This classification is based on their microscopic characteristics. A fourth subtype, the "hemangiolymphangioma" is also recognized.

- Capillary lymphangiomas

- Cavernous lymphangiomas

- Cystic hygromas

- Hemangiolymphangioma

Lymphangiomas may also be classified into "microcystic", "macrocystic", and "mixed" subtypes, according to the size of their cysts.

- Microcystic lymphangiomas

- Macrocystic lymphangiomas

- Mixed lymphangiomas

Finally, lymphangiomas may be described in stages, which vary by location and extent of disease. In particular, stage depends on whether lymphangiomas are present above or "superior" to the hyoid bone ("suprahyoid"), below or "inferior" to the hyoid bone ("infrahyoid"), and whether the lymphangiomas are on one side of the body ("unilateral") or both ("bilateral").

- Stage I: Unilateral infrahyoid.

- Stage II: Unilateral suprahyoid.

- Stage III: Unilateral suprahyoid and infrahyoid.

- Stage IV: Bilateral suprahyoid.

- Stage V: Bilateral suprahyoid and infrahyoid.

A cirsoid aneurysm is the dilation of a group of blood vessels due to congenital malformations with AV (arterio venous) shunting. Cirsoid means resembling a varix.

Sometimes, a minor traumatic episode, such as a fall or bump on the head, can lead to the formation of a cirsoid aneurysm. Often these are trivial traumatic episodes

Cirsoid aneurysm, in general, is a hemangioma of an artery. It most commonly occurs over the head, usually the superficial temporal artery and also its branches. It can also occur in places where medium vessels lie over bones without much intervening tissues between them and the skin.

The superficial temporal artery is the most commonly involved artery.

People with visible marks generally feel fine (physically) and can act normally, but when it is mentioned, they may become withdrawn and self-conscious. Some children may have low self-esteem due to the condition.

CMTC is an uncommon, sporadic congenital vascular malformation characterized by a generalized or localized reticulated cutaneous vascular network.

Cutaneous lesions described in patients with CMTC include nevus flammeus, hemangioma, nevus anemicus, café-au-lait spots, melanocytic nevus, aplasia cutis and acral cyanosis.

It has a marbled bluish to deep-purple appearance. The dark skin lesions often show a palpable loss of dermal substance. The reticulated mottling frequently appears more prominent in a cold environment (physiologic cutis marmorata), but tends not to disappear with warming. Hence, the erythema may be worsened by cooling, physical activity, or crying.

CMTC frequently involves the extremities, with the lower extremities involved most commonly, followed by the upper extremities, and then the trunk and face. The lower extremities often show atrophy and seldom show hypertrophy resulting in limb circumference discrepancy.

When located on the trunk, the lesions of CMTC tend to show mosaic distribution in streaks with a sharp midline demarcation seen across the abdomen. The lesions are primarily localized, but can be segmental or generalized, often unilateral in appearance. Diffuse involvement of the skin is usually not observed.

Although its course is variable, the majority of lesions in mild cases fade by adolescence. Ulceration and secondary infection are complications in severe cases and can be fatal if present in the neonatal period.

A hematoma (US spelling) or haematoma (UK spelling) is a localized collection of blood outside the blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is initially in liquid form spread among the tissues including in sacs between tissues where it may coagulate and solidify before blood is reabsorbed into blood vessels. An ecchymosis is a hematoma of the skin larger than 10mm.

They may occur among/within many areas such as skin and other organs, connective tissues, bone, joints and muscle.

A collection of blood (or even a hemorrhage) may be aggravated by anticoagulant medication (blood thinner). Blood seepage and collection of blood may occur if heparin is given via an intramuscular route; to avoid this, heparin must be given intravenously or subcutaneously.

It is not to be confused with hemangioma, which is an abnormal buildup/growth of blood vessels in the skin or internal organs.

Microvenular hemangioma (also known as "Microcapillary hemangioma") is an acquired benign vascular neoplasm that presents as an asymptomatic, slowly growing, 0.5- to 2.0 cm reddish lesion on the forearms or other sites of young to middle-aged adults.

Clinical symptoms of CNS origin include recurrent headaches, focal neurological deficits, hemorrhagic stroke, and seizures, but CCM can also be asymptomatic. The nature and severity of the symptoms depend on the lesion's location.

Cutis marmorata telangiectatica congenita or CMTC is a rare congenital vascular disorder that usually manifests in affecting the blood vessels of the skin. The condition was first recognised and described in 1922 by Cato van Lohuizen, a Dutch pediatrician whose name was later adopted in the other common name used to describe the condition - Van Lohuizen Syndrome. CMTC is also used synonymously with congenital generalized phlebectasia, nevus vascularis reticularis, congenital phlebectasia, livedo telangiectatica, congenital livedo reticularis and Van Lohuizen syndrome.

It should not be confused with the more general term "cutis marmorata", which refers to livedo reticularis caused by cold.

In the eye, it is known as orbital cavernous hemangioma and is found in women more frequently than men, most commonly between the ages of 20-40. This neoplasm is usually located within the muscle cone, which is lateral to the optic nerve. It is not usually treated unless the patient is symptomatic. Visual impairment happens when the optic nerve is compressed or the extraocular muscles are surrounded.

A capillary hemangioma (also known as an Infantile hemangioma, Strawberry hemangioma, and Strawberry nevus) is the most common variant of hemangioma which appears as a raised, red, lumpy area of flesh anywhere on the body, though 83% occur on the head or neck area. These marks occur in about 10% of all births, and usually appear between one and four weeks after birth. It may grow rapidly, before stopping and slowly fading. Some are gone by the age of 2, about 60% by 5 years, and 90–95% by 9 years. Capillary hemangioma is a vascular anomaly.

Capillary hemangiomas occur 5 times more often in female infants than in males, and mostly in Caucasian populations. Additionally, low birthweight infants have a 26% chance of developing a hemangioma.

It is the most common tumor of orbit and periorbital areas in childhood. It may occur in the skin, subcutaneous tissues and mucous membranes of oral cavities and lips as well as in the liver, spleen and kidneys. While this birthmark may be alarming in appearance, physicians generally counsel that it be left to disappear on its own, unless it is in the way of vision or blocking the nostrils.

Cavernous hemangiomas are the most common benign tumors of the liver. Usually one tumor exists, but multiple lesions can occur in the left or right lobe of the liver in 40% of patients. Their sizes can range from a few millimeters to 20 centimetres. Those over 5 cm are often referred to as "giant hemangiomas".

A tufted angioma (also known as an "Acquired tufted angioma," "Angioblastoma," "Angioblastoma of Nakagawa," "Hypertrophic hemangioma," "Progressive capillary hemangioma," and "Tufted hemangioma") usually develops in infancy or early childhood on the neck and upper trunk, and is an ill-defined, dull red macule with a mottled appearance, varying from 2 to 5 cm in diameter.

Typically not diagnosed until late childhood or later, Bonnet–Dechaume–Blanc syndrome usually presents itself with a combination of central nervous system features (midbrain), ophthalmic features (retina), and facial features. The degree of expression of the syndrome's components varies both clinically and structurally. Common symptoms that lead to diagnosis are headaches, retro-orbital pain and hemianopia.

The ophthalmic features of the Bonnet–Dechaume–Blanc syndrome occur as retinal arteriovenous malformation (AVMs). There are three categories of AVMs that are categorized depending on the severity of the malformation. The first category consists of the patient having small lesions that usually are asymptomatic. The second category, more severe than the first, is when the patient’s malformation is missing a connecting capillary. The missing capillary is meant to serve as a link between an artery and a vein; without it, edemas, hemorrhages, and visual impairments can result. Category three, the most severe, occurs when the patient’s malformations are so severe that the dilated vessels cause no distinction between artery and vein. When the symptoms are this severe, the patient has a significantly increased risk of developing vision loss. Since the retinal lesions categorized vary from large vascular malformations that affect a majority of the retina to malformations that are barely visible, the lesions cause a wide range of symptoms including decrease in visual sharpness, proptosis, pupillary defects, optic degeneration and visual field defects. The most common type of visual field impairment due to AVMs is homonymous hemianopia. Homonymous hemianopia typically presents unilaterally, but bilateral cases have been reported as well.

The extent of the central nervous system (CNS) features/symptoms of Bonnet–Dechaume–Blanc syndrome is highly dependent of the location of the cerebral AVMs and the extent of the malformation. The most common symptom affecting the CNS is an intracranial hemangioma in the midbrain. Along with hemangiomas, the malformations result in severe headaches, cerebral hemorrhages, vomiting, meningism, seizures, acute strokes or progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting.

The distinguishable facial features that result from Bonnet–Dechaume–Blanc syndrome vary from case to case. A person showing signs of the syndrome may display faint skin discoloration, nevi and angiomas of the skin. Some patients with this disorder also present with high flow arteriovenous malformations of the maxillofacial or mandibular (jaw) regions. Another facial indicator of this disease is malformations affecting the frontal and/or maxillary sinuses.

Pyogenic granuloma (also known as a "eruptive hemangioma", "granulation tissue-type hemangioma", "granuloma gravidarum", "lobular capillary hemangioma", "pregnancy tumor", and "tumor of pregnancy") is a vascular lesion that occurs on both mucosa and skin, and appears as an overgrowth of tissue due to irritation, physical trauma, or hormonal factors. It is often found to involve the gums, the skin and nasal septum, and has also been found far from the head such as in the thigh.

Hemangiomas associated with PHACE Syndrome are usually small or not visible at birth, but are easier to see during the first days to weeks of life. They can grow rapidly. Hemangiomas linked with PHACE Syndrome tend to cover a large area of the face, head or neck, either as one lesion or as many single lesions.

The appearance of pyogenic granuloma is usually a color ranging from red/pink to purple, and can be smooth or lobulated. Younger lesions are more likely to be red because of the high number of blood vessels. Older lesions begin to change into a pink color. Size commonly ranges from a few millimeters to centimeters, though smaller or larger lesions may occur. A pyogenic granuloma can be painful, especially if located in an area of the body where it is constantly disturbed. Pyogenic granulomas can grow rapidly and will often bleed profusely with little or no trauma. They may exude an oil like substance, causing the surface to be damp. This is especially true if the granuloma is located on the scalp.

Pyogenic granulomas may be seen at any age, and are more common in females than males. In pregnant women, lesions may occur in the first trimester with an increasing incidence up until the seventh month, and are often seen on the gums. Epulis granulomatosum is a variant of pyogenic granuloma that forms only on gingiva, and is often seen forming in a recent extraction socket. Pyogenic granulomas appear on the gingiva in 75% of cases, more often in the maxillary than mandibular jaw. Anterior areas are more often affected than posterior areas. It can also be found on the lips, tongue, and inner cheek. Poor oral hygiene or trauma are usually precipitating factors.

One study has suggested a correlation between pyogenic granulomas and Bartonella seropositivity. However, this association has been questioned by others. The microscopic appearance of a pyogenic granuloma consists of highly vascular granulation tissue. Inflammation is present. The lesion may have a fibrous character if it is older, and the surface may have ulcerations. Pyogenic granulomas rarely occur in the conjunctiva, cornea or connective tissue of the eye following minor local trauma. Grossly these mass lesions resemble those occurring at more common sites. The relationship of these lesion to lobular capillary hemangiomas of skin and oropharyngeal mucosa commonly referred to as pyogenic granuloma is uncertain.

Cherry angiomas are made up of clusters of capillaries at the surface of the skin, forming a small round dome ("papule") , which may be flat topped . They range in colour from bright red to purple. When they first develop, they may be only a tenth of a millimeter in diameter and almost flat, appearing as small red dots. However, they then usually grow to about one or two millimeters across, and sometimes to a centimeter or more in diameter . As they grow larger, they tend to expand in thickness, and may take on the raised and rounded shape of a dome. Multiple adjoining angiomas are said to form a "polypoid angioma". Because the blood vessels comprising an angioma are so close to the skin's surface, cherry angiomas may bleed profusely if they are injured.

One study found that the majority of capillaries in cherry hemangiomas are fenestrated because of staining for carbonic anhydrase activity.

Central nervous system cavernous hemangioma is a cavernous hemangioma that arises in the central nervous system (CNS). It can be considered to be a variant of hemangioma, and is characterized by grossly large dilated blood vessels and large vascular channels, less well circumscribed, and more involved with deep structures, with a single layer of endothelium and an absence of neuronal tissue within the lesions. These thinly walled vessels resemble sinusoidal cavities filled with stagnant blood. Blood vessels in patients with cerebral cavernous malformations (CCM) can range from a few millimeters to several centimeters in diameter. Most lesions occur in the brain, but any organ may be involved.

The afflicted may have relatively small amounts of pain that will quickly increase in severity over a time period of 6–12 weeks. The skin temperature around the bone may increase, a bony swelling may be evident, and movement may be restricted in adjacent joints.

Spinal lesions may cause quadriplegia and patients with skull lesions may have headaches.

As it grows, the hemangioma can break down skin, distort facial features or get in the way of other vital functions, such as breathing, vision, and hearing. Other complications will depend on what other structures are involved. These could include developmental delay, seizures, headaches, and abnormal muscle tone if the brain is involved.

Bonnet–Dechaume–Blanc syndrome, also known as Wyburn-Mason syndrome, is a rare congential arteriovenous malformation of the brain, retina or facial nevi. The syndrome has a number of possible symptoms and can affect the skin, bones, kidneys, muscles, and gastrointestinal tract. When the syndrome affects the brain, people can experience severe headaches, seizures, acute stroke, meningism and progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting.

As for the retina, the syndrome causes retinocephalic vascular malformations that tend to be present with intracranial hemorrhage and lead to decreased visual acuity, proptosis, pupillary defects, optic atrophy, congestion of bulbar conjunctiva, and visual field defects. Retinal lesions can be unilateral and tortuous, and symptoms begin to appear in the second and third decades of life.

The syndrome can present cutaneous lesions, or skin with different texture, thickness, and color, usually on the face. The facial features caused by the syndrome vary from slight discoloration to extensive nevi and angiomas of the skin. In some cases, the frontal and maxillary sinus can present problems in the subject due to the syndrome.

There have only been 52 reported cases of patients with Bonnet–Dechaume–Blanc syndrome as of 2012. Symptoms are rarely noticed in children and the syndrome is often diagnosed in late childhood or early adulthood when visual impairment is noticed. Fluorescein angiography is commonly used to diagnose the syndrome.

There have been several methods in treating patients who display Bonnet–Dechaume–Blanc syndrome. However, which method seems to work the most is within argument. Patients with intracranial lesions have been treated with surgical intervention and in some cases, this procedure has been successful. Other treatments include embolization, radiation therapy, and continued observation.

With limited research on Bonnet–Dechaume–Blanc syndrome, researchers have focused on the clinical and radiological findings rather than how to manage this rare and non-heritable syndrome.