What is the cause of nevi?

Moles (nevi) are a common type of skin growth. They often appear as small, dark brown spots and are caused by clusters of pigment-forming cells (melanocytes). Most people have 10 to 40 moles that appear during childhood and adolescence and may change in appearance or fade over time.

What causes neurocutaneous melanosis?

This mutation may be due to abnormal expression of hepatocyte growth factor/scatter factor by the mesenchymal cells within the neural crest. Another proposed cause of neurocutaneous melanosis is a mutation of the NRAS gene at codon 61.

What causes congenital melanocytic nevi?

Causes. Congenital nevi are thought to be caused by a genetic mutation, called a sporadic mutation, which develops randomly as a baby grows in the womb. The condition is not inherited.

What is CMN syndrome?

Congenital melanocytic nevi (CMN) are visible pigmented (melanocytic) proliferations in the skin that are present at birth. CMN are benign, tumor-like malformations resulting from faulty development of pigment cell (melanocyte) precursors in the embryo, and composed of an abnormal mixture of skin elements.

How do you describe nevi?

A benign (not cancer) growth on the skin that is formed by a cluster of melanocytes (cells that make a substance called melanin, which gives color to skin and eyes). A nevus is usually dark and may be raised from the skin. Also called mole.

What is Neurocutaneous Melanocytosis?

Neurocutaneous melanosis (NCM) is a rare, non-inherited condition of the central nervous system. It is characterized by melanocytic nevi in both the skin and the brain. Two-thirds of people with NCM have giant congenital melanocytic nevi, and the remaining one-third have numerous lesions but no giant lesions.

What is Neurocutaneous melanoma?

Neurocutaneous melanoma is a rare congenital syndrome associated with congenital melanocytic nevi with meningeal melanosis or melanoma. The disease is aggressive and has a high propensity for leptomeningeal metastases.

What does a congenital nevi look like?

A congenital nevus looks like a round or oval-shaped patch of colored skin and is usually raised. They can be either a single color or multi-colored. They can vary in size from a tiny spot to something that covers a large part of your body. In some cases, they might have hair growing out of them.

Is CMN treatable?

CMN can also be lightened with laser therapy or chemical peels. However, these treatments may not be permanent. Furthermore, lightened moles may also be harder to track for skin cancer risk. The only true “cure” for skin cancer risk of CMN is to remove the mole.

Can you get rid of CMN?

Small nevi can be removed by simple surgical excision. The nevus is cut out, and the adjacent skin stitched together leaving a small scar. Removal of a large congenital nevus, however, requires replacement of the affected skin.