Melanocitic nevus

Melanocitic nevus (mole) is a benign tumor or a hamartom composed of melanocytes, the pigment-producing cells that colonize the skin formation. Melanocytes are derived from neural crest and migrate into the embryo in selected ectodermal sites (first in the epidermis and into the central nervous system) as well as the eyes and ears. Ectopic melanocytes have been identified in gastrointestinal and genitourinary tracts.
Melanocitici congenital nevi (moles occurred at birth) are considered to be a malformation or abnormality in embryogenesis and hamartoame. In contrast mjoritatea melanocitici earned nevi are considered benign neoplasms. Melanocitici nevi occur in all mammalian species and are common in humans, dogs and horses. Analogue melanocitic nevus is malignant melanoma. Melanocitici earned nevi (moles occurred during life) are so frequently encourage some doctors believe that they can not be considered a defect or an anomaly. Yet despite the high prevalence, melanocitici nevi are pathological because it is an aberrant or neoplastic cell proliferation. Most people with lighter skin have at least a few nevi. Melanocitici nevi occur in people with darker skin, but with a low prevalence.
Moles are completely benign. However they can be found in association with melanoma. Frequency of moles in melanoma true transformation is not known and estimated prevalence varies widely. In some studies is very low while in others up to 40%. Both earned and congenital nevi maintained a risk of developing melanoma. Congenital moles are at higher risk.
Large and giant moles biological and cosmetic implications. They have a low but real risk of malignant transformation and development of melanoma. Some authorities believe that melanoma may develop in a giant congenital nevus to 5% of cases. Melanotici nevi are common lesions in patients with lighter skin and thinner and more rare in those with dark skin. This difference in prevalence is partly attributed to the fact that the identification of nevi in patients with black skin is difficult, especially if they are flat. It was suggested that nevi are melanocitici part stimulated by exposure to sunlight. When people with darker skin have less melanin nevi due protection.
Studies show that creams with high SPF sun shielding attenuates the development and evolution of moles when used in children. Therefore, people with dark skin sample is due pretectie melanizarii own against the development of skin moles. Medical treatment is typically ineffective and inappropriate as a benign neoplasm melanocitic nevus (mole). Melanocitici nevi can be removed surgically for cosmetic reasons or because of malignant potential. Nevi are often removed for cosmetic removed by tangential excision. Excision point can be used for relatively small lesions. Large lesions may require complete excision with suture
Pathogenesis of moles Melanocytes are present in the basal layer of epidermis and shows a degree of territoriality. Non-neoplastic melanocytes shows typical contact inhibition to each other and therefore pigment cells are never found in groups. Moles are proliferations of melanocytes that are in contact with each other forming small collections of cells known as nesting. Moles are usually formed during early childhood. Their debut is considered to be a response to sun exposure. Yet there is a genetic factor involved in the development of some types of nevi melanocitici. Some express an autosomal dominant condition (dysplastic nevus syndrome or familial multiple mole melanoma syndrome), in which members have an increased number of nevi, sometimes one hundred scattered on the skin.
Melanocitici nevi were observed to grow rapidly after veziculizare diseases (two to three degree burns, toxic epidermal necrolysis) or people with genetic diseases such as epidermolysis buloza veziculizare. In such cases so called nevi melanocitici erputivi dezvvoltarea probably propagated by a traumatic stimulus. Growth factors such as fibroblast growth factor were considered to be released by keratinocytes that proliferate and can stimulate the proliferation of melanocytes. Melanocitici neoplasms benign nevi are earned. Congenital nevi are best understood genetic malformations. Melanocytes derived from neural crest and congenital nevi is probably an error in neuroectodermal development and migration of these elements. Melanocitice nevice cells can be observed in lymph nodes and capsules can be confused with metastatic deposits due to extracutaneous location. The cellular debris associated with congenital nevi or those big blue.