A nevus cell nevus is a subtype of benign pigmented nevi (moles, liver spots) that consist of a sharply demarcated collection of nevus cells. Nevocytes are melanocyte-like cells, but cannot release their produced melanin to other skin cells. Nevus cell nevi usually form after birth and go through three typical stages of development until adulthood. Nevus cell nevi are usually harmless but can develop into malignant melanomas.
What is a nevus cell nevus?
Externally, a nevus cell nevus is no different from a so-called lentigo simplex, a pigmented patch composed of melanocytes. Nevus cell nevi (NCN) are sharply circumscribed pigmentary nevi of the skin that consist of nevus cells and are brownish to almost black in color. Externally, a nevus cell nevus does not differ from a so-called lentigo simplex, a pigment spot consisting of melanocytes. In principle, RCCs can degenerate and cause skin cancer. Nevus cells are melanocyte-like cells that, like melanocytes, produce the skin pigment melanin but cannot release it to surrounding cells because they are not connected to surrounding cells by dendrites like melanocytes. Most nevus cell nevi develop after birth and typically go through three distinct stages of development, usually completed after puberty. Special forms of nevus cell nevi can also be observed. For example, these are connatal nevus cell nevi, large nevi that are already present at birth. So-called halo nevi are surrounded by a white-appearing pigmentless ring (halo), but are also normally benign. A Spitz nevus often affects children and adolescents. These rare RNCs are also benign, but quickly grow into a hemispherical, hairless nodule up to one centimeter high. Differentiation from malignant melanoma is often difficult and requires histologic examination for confirmation.
Causes
Well over 90 percent of nevus cell nevi form after birth. They result from gene mutations in the postzygotic stage, i.e., mutations after the female egg cell has united with the male sperm cell. Therefore, NZN are not inherited, but form again in each individual due to certain (as yet) not precisely known genetic changes during the embryonic stage. A small percentage of NZN mature before birth. These nevi, called congenital or connatal NCDs, are usually relatively large in area and usually grow along with the growth of the skin, thus increasing in size over time until the end of the child’s growth phase. The causation of congenital NCDs is the same as that of other NCDs. Environmental conditions, nutrition, and other external factors play no role in the development of NZN.
Diseases with this symptom
- Skin cancer
- Melanoma
Diagnosis and course
A nevus cell nevus is virtually indistinguishable in appearance from a lentigo simplex, which forms from melanocytes. All three stages of development of a RCC present with a slightly different visual appearance in each case, but usually do not cause any symptoms. Predominantly in children and adolescents under the age of twenty, so-called Spitz nevi may also develop. These are characterized by rapid growth and form after a short time a reddish to brown, hemispherical, hairless, nodule with a height of up to about one centimeter. This type of NCN also does not cause any symptoms, however, Spitz NCN are difficult to distinguish from malignant melanoma, so that careful histological examinations and precautionary removal of Spitz NCN are recommended. Nevi formed from nevicells are virtually indistinguishable in appearance from nevi composed of melanocytes. Differentiation would be possible by histologic examination. This is usually not done, because neither NZN nor nevus simplex, as melanocytic nevus is called, require therapy. In most cases, NZNs progress through the three developmental stages: junctional nevus, compound nevus, and dermal nevus until approximately the completion of puberty.
- Junctional nevi usually develop in infancy.They are located between the epidermis and the underlying dermis and appear as punctate, brown to black skin lesions.
- In the next stage, which is often reached during puberty, the NZN penetrates further into the dermis as compound nevus, the pigmentation becomes somewhat more irregular.
- In the final stage, the nevicells sink even deeper into the dermis and the nevus, now called dermal nevus, loses much of the pigmentation, is overgrown with hairs and is mainly visually disturbing.
Basically, the nevus cells of the NZN can degenerate and develop into a malignant melanoma. If a NZN develops into a dysplastic nevus with atypical nevus cells and atypical appearance, this was previously considered a precursor for malignant melanoma. This hypothesis could not be scientifically proven and is therefore no longer held today.
Complications
Nevus cell nevi (NCN) usually present as visible skin changes in the form of roundish, brown to black spots in advanced childhood or adulthood. Basically, they are benign cells that do not tend to degenerate. In many cases, the nevi even regress in the course of life. In so-called dermal RCCs, the nevus cells have descended into the dermis, and the nevus takes on a sharply demarcated, hemispherical shape with a pale red coloration. The possible complication that may result is purely cosmetic if the RCC has formed in an exposed area, such as the face. If left untreated, the dermal nevus does not regress, but merely undergoes a connective tissue-like transformation. If the benignity of the dermal nevus is confirmed, it can be surgically removed without any problems, for example, using electrocaustics. In rare cases, nevus cells can degenerate and form the germ cell for a malignant melanoma, which normally develops from melanocytes and not from nevus cells. The possible development of a RCC into a melanoma can be recognized by their alteration. Typically, a ragged edge forms and the coloration becomes gray or bluish to black. If left untreated, melanoma leads to death due to metastasis to major organs. If melanoma is discovered before metastasis, generous surgical removal can lead to cure.
When should you see a doctor?
A nevus cell nevus (NCN), also called a birthmark or mole, is made up of nevus cells that are usually completely harmless. Similar to melanocytes, they can produce the brown pigment melanin, but they cannot pass it on to other cells. Normally, it is not necessary to see a doctor when NZN appear. If the mole(s) are found to be very disturbing, it is possible to have the cells removed by a specialist for cosmetic reasons. The nevi are then usually cut out deeply using an “electro scalpel” (electrocaustic). However, it must first be perfectly clarified whether it is a harmless NZN. It is advisable to visually inspect your own nevus cell nevi or those of your partner from time to time. Unlike age spots, which are not prone to degeneration, nevus cells can change and cause a malignant skin cancer, malignant melanoma. If RHNs change either shape, color or size in a noticeable way, an experienced dermatologist should be consulted immediately to clarify possible hazards. The conspicuous changes can be clarified according to the so-called ABCDE rule, where the individual letters stand for asymmetry, limitation, colorfulness, diameter and elevation. In case of doubt, a tissue sample taken must provide a confirmed diagnosis, on which therapeutic measures are then based.
Treatment and therapy
In principle, under normal circumstances, RCCs do not require any treatment or therapy. At most, a RCC that is cosmetically disruptive in its final stage as a dermal nevus may be surgically removed. Otherwise, therapy is only indicated if a RCC develops into a malignant melanoma (black skin cancer). Black skin cancer is very aggressive and tends to metastasize, so that after a final histological positive diagnosis, the melanoma must be completely surgically removed and in some cases also the lymph node closest in the lymphatic drainage.Because the tumor tends to metastasize, additional radiation, various immunotherapies, and specific chemotherapies may also be considered.
Outlook and prognosis
In most cases, the nevus cell nevus is a harmless symptom that does not necessarily need to be treated by a physician. In many cases, the symptom also resolves with age and does not lead to further symptoms or complications. However, the patient should observe the nevus cell nevus and always consult a doctor if there are any changes. The change can take place in size, shape and color. If the affected person is dissatisfied with the nevus cell nevus, it can also be removed. For this, a surgical procedure is necessary, but it is without complications. This is especially necessary in the case of a nevus cell nevus if the patient does not feel comfortable with it. Another treatment is necessary only if the nevus cell nevus is a precursor of skin cancer. In this case, it can also be surgically removed. At the same time, the surrounding skin is also checked and treated if necessary. In many cases, radiation therapy is also used for treatment. In most cases, however, the course of the disease is positive. Prevention of nevus cell nevus cannot be performed.
Prevention
Preventive measures against the formation of RCCs are not possible because the causation lies in gene mutations that occur during the embryonic stage. Instead of preventive measures, observation of NZN is indicated to clarify abnormal changes as early as possible.
What you can do yourself
In most cases, a nevus cell nevus is harmless and does not require treatment. Those who find them bothersome can apply some cosmetic measures and home remedies to lighten the moles. Proven home remedies include apple cider vinegar, garlic and bananas applied to the spot overnight. For moles on the face, tea tree oil applied directly to the affected area of skin will help. After a few applications, the nevus cell nevus should lighten and eventually disappear. Lemon juice bleaches the skin and is considered a gentle remedy for pigment disorders. It is enough to drip the skin area several times a day and wash off the lemon juice after a few minutes. Aloe vera acts in a similar way and can also be applied as a gel or juice. If skin irritation occurs, treatment should be discontinued. In the long term, moles can also be reduced by a vitamin-rich and balanced diet. Yogurt and buttermilk are also suitable for internal use. If this does not reduce the nevus cell nevus, a visit to the doctor is recommended. Aggressive treatment measures such as scratching the mole or using irritating preparations should be avoided to prevent complications.