Congenital dermal sinus is a dermal indentation generally present congenitally over the dorsal spine.

The congenital melanocytic nevus appears as a circumscribed, light brown to black patch or plaque, potentially very heterogeneous in consistency, covering any size surface area and any part of the body.

As compared with a melanocytic nevus, congenital melanocytic nevi are usually larger in diameter and may have excess terminal hair, a condition called hypertrichosis. If over 40 cm projected adult diameter with hypertrichosis, it is sometimes called giant hairy nevus; more usually these largest forms are known as large or giant congenital melanocytic nevus. The estimated prevalence for the largest forms is 0.002% of births.

Melanocytic Nevi often grow proportionally to the body size as the child matures. As they mature, they often develop thickness, and become elevated, although these features can also be present from birth. Prominent terminal hairs often form, especially after puberty. With maturity, the nevus can have variation in color, and the surface might be textured with proliferative growths.

Neurocutaneous melanosis is associated with the presence of either giant congenital melanocytic nevi or non-giant nevi of the skin. It is estimated that neurocutaneous melanosis is present in 2% to 45% of patients with giant congenital melanocytic nevi. Neurocutaneous melanosis is characterized by the presence of congenital melanocytic nevi on the skin and melanocytic tumors in the leptomeninges of the central nervous system.

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.

Preauricular sinuses and cysts result from developmental defects of the first and second pharyngeal arches. This and other congenital ear malformations are sometimes associated with renal anomalies. They may be present in Beckwith–Wiedemann syndrome, and in rare cases, they may be associated with branchio-oto-renal syndrome.

Congenital melanocytic nevi may be divided into the following types:

- "Small-sized congenital melanocytic nevus" is defined as having a diameter less than 2 cm.

- "Medium-sized congenital melanocytic nevus" is defined as having a diameter more than 2 cm but less than 20 cm.

- "Giant congenital melanocytic nevus" (also known as "Bathing trunk nevus," "Garment nevus," "Giant hairy nevus", and "Nevus pigmentosus et pilosus") is defined by one or more large, darkly pigmented and sometimes hairy patches.

A preauricular sinus (also known as a congenital auricular fistula, a congenital preauricular fistula, a Geswein hole, an ear pit, or a preauricular cyst) is a common congenital malformation characterized by a nodule, dent or dimple located anywhere adjacent to the external ear. Frequency of preauricular sinus differs depending the population: 0.1-0.9% in the US, 0.9% in the UK, and 4-10% in Asia and parts of Africa. Comparative frequency is known to be higher in Africans and Asians than in Caucasians.

Preauricular sinuses are inherited features, and most often appear unilaterally. They are present bilaterally in 25-50% of cases.

Infantile hemangiopericytoma (also known as "Congenital hemangiopericytoma") is a cutaneous condition characterized by single or multiple dermal and subcutaneous nodules that may be alarmingly large at birth or grow rapidly.

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.

Additional types of nevi do not involve disorders of pigmentation or melanocytes. These additional nevi represent hamartomatous proliferations of the epithelium, connective tissue, and vascular malformations.

They are divided into three types based on their location:

- commissural pits, which are small pits near the labial commissure of the mouth,

- a pit in the upper lip, in which case it may be called a midline sinus of the upper lip, and

- pits in the lower lip, in which case it may be called a congenital sinus of the lower lip.

In some cases commissural pits have been reported in combination with preauricaluar pits, which are near the ear.

Sclerotic fibromas are a cutaneous condition characterized by well-circumscribed, dome-shaped, dermal hypocellular nodules composed predominantly of sclerotic thick collagen bundles.

The term "nevus" is applied to a number of conditions caused by neoplasias and hyperplasias of melanocytes, as well as a number of pigmentation disorders, both hypermelanotic (containing increased melanin, the pigment responsible for skin color) and hypomelanotic (containing decreased melanin).

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.

During the first few weeks after birth, when the lesions are not very reticulated, CMTC may look very similar to vascular lesions such as port-wine stains. However, during follow-up, CMTC lesions become characteristic in their appearance. They must be differentiated from other causes of persistent reticulated vascular lesions, such as those in the following table:

This condition is characterised by symmetrical lesions on the temples resembling forceps marks. It is characterized a puckered skin due to a virtual absence of subcutaneous fat. It is apparent at birth. Other lesions that may be present include puffy, wrinkled skin around the eyes and/or abnormalities of the eyelashes, eyebrows, and eyelids. The eyebrows may be up slanting or outward slanting. Occasionally the bridge of the nose may appear flat, while the tip may appear unusually rounded. The chin may be furrowed. The upper lip may be prominent with a down turned mouth. Other features that have been reported include dysplastic and low set ears, linear radiatory impressions on the forehead and congenital horizontal nystagmus.

Those with the Setleis syndrome may be missing eyelashes on both the upper and lower lids or may have multiple rows of lashes on the upper lids but none on the lower lids.A possible association with intra abdominal cancer has been reported but to date this has not been confirmed in other studies.

A "hemangioma of infancy", colloquially called a strawberry mark, is a benign self-involuting tumor (swelling or growth) of endothelial cells, the cells that line blood vessels. It usually appears during the first weeks of life and resolves by age 10. It is the most common tumor of infancy.

PHACES Syndrome, a rare condition that often involves brain, heart, and arterial abnormalities, is generally accompanied by the presence of large facial hemangiomas. In such cases, what appears to be a small bruise or birthmark may grow rapidly and take on a puffy appearance in the first days or weeks of life.

Midline cervical clefts are a rare congenital anomaly resulting from incomplete fusion during embryogenesis of the first and second branchial arches in the ventral midline of the neck. The condition presents as a midline cutaneous defect of the anterior neck with a skin projection or sinus, or as a subcutaneous erythematous fibrous cord. Surgical excision is the preferred treatment.

Port-wine stains, also known as nevus flammeus and sometimes mistaken for strawberry marks, are present at birth and range from a pale pink in color, to a deep wine-red. Irregular in appearance, they are usually quite large, and caused by a deficiency or absence in the nerve supply to blood vessels. This causes vasodilation, the dilation of blood vessels, causing blood to pool or collect in the affected area. Over time, port-wine stains may become thick or develop small ridges or bumps, and do not fade with age. Such birthmarks may have emotional or social repercussions. Port-wine stains occur in 0.3% of the population, equally among males and females. They frequently express unilaterally, i.e., on only one side, not crossing the midline of the body. Often on the face, marks on the upper eyelid or forehead may be indicative of a condition called Sturge-Weber syndrome. Additionally, port-wine stains in these locations may be associated with glaucoma and seizures.

Phakomatosis pigmentovascularis is subdivided into five types:

- Type 1 PWS + epidermal nevus

- Type 2 (most common): PWS + dermal melanocytosis +/- nevus anemicus

- Type 3: PWS + nevus spilus +/- nevus anemicus

- Type 4: PWS + nevus spilus + dermal melanocytosis +/- nevus anemicus

- Type 5: CMTC (Cutis marmorata telangiectatica congenita) + dermal melanocytosis

They all can contain capillary malformation. Type 2 is the most common and can be associated with granular cell tumor. Some further subdivide each type into categories A & B; with A representing oculocutaneous involvement and subtype B representing extra oculocutaneous involvement. Others have proposed fewer subtypes but currently this rare entity is mostly taught as having five subtypes currently.

Phakomatosis pigmentovascularis is a rare neurocutanous condition where there is coexistence of a capillary malformation (port-wine stain) with various melanocytic lesions, including dermal melanocytosis (Mongolian spots), nevus spilus, and nevus of Ota.

A congenital lip pit or lip sinus is a congenital disorder characterized by the presence of pits and possibly associated fistulas in the lips. They are often hereditary, and may occur alone or in association with cleft lip and palate, termed Van der Woude syndrome.

Presentation includes telangiectasia, acanthosis, and hyperkeratosis.

Presentation can be solitary or systemic.

In some instances nodular angiokeratomas can produce necrotic tissue and valleys that can harbor fungal, bacterial and viral infections. Infections can include staphylococcus. If the lesion becomes painful, begins draining fluids or pus, or begins to smell, consult a physician. In these instance a doctor may recommend excision and grafting.

Papillary eccrine adenoma (also known as "tubular apocrine adenoma") is a cutaneous condition characterized by an uncommon benign sweat gland neoplasm that presents as a dermal nodule located primarily on the extremities of black patients.

Congenital malformations of the dermatoglyphs are a cutaneous condition divided into four main categories based on the appearance of the dermal ridges of which they are composed: (1) ridge aplasia; (2) ridge hypoplasia; (3) ridge dissociation; and (4) ridges-off-the-end.