Nevi (commonly known as moles) are the clinical manifestation of the benign proliferation of cells that are normally found on the skin. Moles are present in all people. Some moles can be present at birth (congenital nevi), while others develop during the first decades of life (acquired nevi).
Moles can appear anywhere on the human body. They are more common, however, in parts of the body that are exposed to sunlight. The number and the type of moles depend on genetic factors (heredity), while sun exposure can affect their appearance.
Moles are quite common. All people have such spots on their skin, and in some cases moles occur in large numbers. Patients with moles usually visit a physician both for cosmetic and medical reasons, as they are concerned about their nature. Many of the moles can be diagnosed with a simple visual inspection by a dermatologist. The Dermatologist is the most competent person to determine whether the mole is benign or suspicious. The Dermatologist will determine whether the mole requires just a simple monitoring or should be removed and which should be the method of removal i.e., surgical excision, laser or shave excision.
Nevus – Congenital melanocytic nevus
The congenital melanocytic nevus is present at birth, in about 1% of all newborns and persists throughout life. The congenital nevus presents a large variety in size and can reach a diameter of several centimeters, while – quite rarely – it can cover the entire skin. Nevertheless, most congenital nevi are small, although almost always are more than 1 cm and resemble the acquired nevi. The nevus is round or oval-shaped with spots on the surface of the skin and its coloration may vary from slight pigmentation that resembles the tan from sunbathing to moderate or highly brown. The congenital nevus can be small-sized (< 1.5 cm.), medium-sized (1.5‑10 cm.) and giant (>20 cm.). Often inside the nevus are two shades, of which the deepest occupies the center. In some cases the congenital nevus is hairy.
The main concern regarding the congenital nevus is its precancerous potential. It is certain that there is a very high risk for developing malignant melanoma on such nevi. This possibility is greater for giant congenital nevi. Nevertheless, the risk from congenital melanocytic nevi is small.
Nevus – Acquired melanocytic nevus
Melanocytic nevi, also called nevocellular/nevocytic nevi (common moles) are small, clearly defined, pigmented spots or papules. Depending on the cells that comprise these nevi, they are distinguished in the following types:
Nevi – Junctional melanocytic nevi
These nevi are spots or lesions with minimal elevation above the level of the skin. The color of the nevi is light brown or dark brown, with uniform pigmentation. Their shape is round or oval with smooth borders. Usually these nevi are randomly distributed, although their localization is clearly more frequent in sun exposed areas (trunk, hands, legs, and sometimes the palms and soles).
The nevus with junctional activity has the potential for malignant transformation. This is very rare for such nevi, especially if one takes into account that the average person has at least 25 moles on his/her body.
Nevi – Compound melanocytic nevi
They are usually dark colored nevi and are raised above the surface of the skin. These nevi are round, dome-shaped, smooth, sometimes with papular or hyperkeratotic appearance and they can be hairy. These nevi are most commonly found on the face, head, trunk and the extremities.
Nevi – Dermal or intradermal nevi
This type of nevi are raised. They can be brown, light brown or skin-colored and are round or dome-shaped. Such nevi are usually observed on the face and neck, but they can also be found on the trunk or the extremities. They very rarely transform.
Nevi – Melanocytic halo nevi or Sutton nevus
This is a nevus – usually of brown or light brown color – which is surrounded by a zone of depigmentation. The nevus often disappears spontaneously. It might constitute a vitiligo precursor, as approximately 18‑26% of people who present this nevus, may also develop vitiligo. The presence of a white halo around a nevus is an immunological skin reaction trying to fight the nevus. Because a similar zone of depigmentation develops also in many melanomas, the diagnosis of such a nevus should be done very carefully by a Dermatologist.
Blue nevus is an acquired, benign, blue or grey-black lesion or nodule that usually appears in childhood or late adolescence. This type of nevus requires close monitoring, as in some cases it can lead to malignant skin melanoma.
Spitz nevus is a benign, dome-shaped, hairless small nodule, pink or light brown in color. The characteristic of this nevus is that it develops and grows rapidly within a few months. It is common in children and its distribution mainly involves the head and the neck.
The Nevocellular nevus is a melanocytic spot bearing numerous smaller dark brown spots or papules. This nevus can lead to melanoma in 5% of the cases and, therefore, close monitoring and removal of the nevus is required.
Becker’s nevus is a skin disorder that predominantly affects men. The nevus firstly appears as an irregularly shaped pigmented spot on the upper arm or the upper torso (though other areas of the body can be affected), which gradually enlarges irregularly and can have dense and thick hairs on its surface.
Nevus of Ota – Nevus of Ito
The nevus of Ota is a guttate-type black plaque of skin which can have blue or dark brown color. It is a very common nevus in Asian populations and may be present at birth but it is not hereditary. There are mainly found around the eye area (periocular region) and the upper jaw (maxillary region). When this nevus is located on the shoulder it is known as nevus of Ito.
Nevus – Epidermal nevus
The epidermal nevus is being presented at birth or within the first decade of life and may grow in size during puberty. The epidermal nevus has the color of the skin and is most often found at the upper body. It has no malignant potential.
Nevus – Comedo nevus (Comedone nevus)
The comedo nevus is the manifestation of hair follicle disorder, resulting in the development of many comedones with linear arrangement. It usually appears in childhood or adulthood as a single lesion, which has a linear pattern. It can be found on the face or it appears in the form of multiple lesions on the neck, trunk and arms.
Nevus – Sebaceous
The sebaceous nevus is a raised, yellow or orange, hairless patch, surrounded by many small protuberances. The most common site of localization is the scalp. The nevus occurs at birth and is sensitive to androgens. It increases in size during childhood as do the sebaceous glands, but then regresses until puberty when again increases in size, reaching its maximum size. Because there is a risk of future transition to basal skin cancer, preventive removal of the nevus is recommended during the second or third decade of life.
Nevus – Vascular
Vascular nevus is a well-demarcated tumor, intensely red in color and of round shape. The vascular nevus may be present at birth or appear later, and reaches its maximum size at 6 months of life.
The most common site of localization is the head and neck, but it can appear in any part of the body. It occurs more frequently in premature infants and is considered to be an embryonic angioblast developmental abnormality. The vascular nevus may bleed at times. This bleeding usually subsides by applying topical pressure. If the nevus does not regress spontaneously, its residues may be surgically removed during the second decade of life. Alternatively, the treatment with systematic corticosteroids or beta blockers may help in childhood, especially for those vascular nevi that bleed and present severe symptomatology.
Smooth hemangioma (Port – Wine Stain)
Port-wine stain (nevus flammeus) is not a true nevus. It is a vascular lesion, usually flat, red in color and of irregular shape which varies in size and usually appears on one side of the body (one-sided). The nevus is present at birth and may be found in any part of the body, but most commonly occurs on the face and neck.
The Mongolian spot is not a true nevus. It is a grayish lesion, characteristically localized in the lumbosacral region, but can also appear on the scalp or anywhere on the skin. It is usually a single lesion, but rarely there are several trunk lesions present at birth. The nevus disappears after a certain period of time.
In order to assess the degree of risk we take into account the following factors:
Α (Asymmetry): nevi in which the two halves of the lesion are different (asymmetrical) potentially carry a higher risk to develop malignant transformation.
Β (Borders): nevi in which the borders of the lesion are not uniform but irregular, scalloped or notched require further attention.
C (Color): nevi which do not have a homogenous color distribution, but contain multiple colors such as red, pink, brown, blue and black, require systematic monitoring.
D (Diameter): nevi whose diameter exceeds 6 mm are more likely to undergo malignant transformation.
E (Elevation/Evolution): it is imperative to immediately visit a dermatologist if a nevus presents any change from its original morphology. If the nevus grows, presents symptoms such as itching, pain or edema, is strange to the touch, has a change in color (depigmentation or hyperpigmentation), bleeds or shows a change in sensation visit a dermatologist.
Nevi – Dermoscopy
The particular importance of the early diagnosis of melanoma is significantly facilitated by means of dermoscopy (dermatoscopy). This is the gold standard method (first-choice examination) for the examination of moles so as to achieve early detection of skin melanoma. Mole dermoscopy is a diagnostic, non invasive, imaging technique applied with a special tool, the dermoscope. We apply it on the nevi after a special oil, gel or water has been applied. In this way we are able to focus on the morphological characteristics of the structure and color of the lesions that are not visible to the naked eye, with the highest possible magnification for the detection of malignancy.
Nevi – Mole mapping
ΆMapping is another method for the examination of nevi. Mapping is advantageous over dermoscopy, as it allows the evaluation of the progression of nevi and pigmented lesions over time. Mole mapping is the most reliable method for early diagnosis of skin cancer. The moles of the body are recorded. This is achieved by the use of digital photography, analysis and data preservation in a computer with the aid of specialized software. These images can be compared with older images in following appointments for re-examination. Mole mapping should be performed once a year, unless a more frequent examination is deemed necessary.
Nevi – Biopsy
Finally, any suspected for malignancy nevus that is removed, should be sent for biopsy in order to accurately evaluate mole histology, determine if there are atypical cells present and if the mole has been excised on healthy (tissue) boundaries.
People with high risk of developing malignant melanoma should routinely monitor their moles. Such people are:People having numerous moles (more than 50)
People with a family history of skin cancer or melanoma
People with a personal history of skin cancer or melanoma
People with light skin phototype (phototype 1 and phototype 2) and thus having many moles
People with a history of sunburn, particularly in childhood or adolescence
People who develop giant congenital melanocytic nevus
People with dysplastic nevus syndrome. This term refers to a syndrome which is characterized by the presence of a high number of atypical nevi on the body.
Atypical nevi are those who have a larger size compared to common nevi, they vary in color and contour with an ill-defined border. Dysplastic nevi appear in childhood and their clinical features change in puberty. Dysplastic nevi have a 6% higher risk of transformation compared to common nevi. This percentage increases to 15% if a positive family history coexists. Thus, monitoring of a dysplastic nevi at regular intervals by a dermatologist is imperative.
The following are the ways for nevi removal:
Mole removal with laser
Not all moles are suitable for removal by laser. A mole can be removed in this way only if it is absolutely certain that is a benign lesion (nevi without risk for transformation, papillomas, freckles, seborrheic warts, etc.). In this case laser removal is advantageous as the lesion can be removed with the formation of a scar. However, if there is any suspicion for malignancy, the mole should be surgically removed by fusiform excision entirely on healthy borders and sent for biopsy. Although laser removal of moles is more superficial, it usually leaves no scars.
Shave excision of moles
Shave excision is a simple and fast way of removal, where – after local anesthesia with xylocaine solution – the protruding part of the nevus is removed with a sharp blade. Hemostasis and additional removal of any residual portion can be achieved with CO2 laser or diathermy.
Surgical removal of nevi
When the nevi are flat or when there is suspicion of malignancy, preventive surgical nevus excision is recommended. Moreover, it is performed excision of the boundaries surrounding the nevus by a plastic surgeon so as the block to be sent for biopsy.
The recommended method of removal should be decided after discussion with the dermatologist. The scar that will remain depends on its size, the method of its removal and the healing capacity of the body.
Moles (nevi) – Why choose Cosmetic Derma Medicine for the assessment and removal of my moles (nevi)?
The Plastic Surgeon Dr. Anastasios Vekris, is the Director of the Department of Plastic Surgery in Cosmetic Derma Medicine. Dr. Vekris and his medical team guarantee the best aesthetic result in the surgical removal of moles (nevi).