Melanoma is a form of skin cancer that occurs in the melanocytes (pigment producing cells) in the epidermis. Though common in the skin layers, it may also develop in the eyes and the intestine. In men, it usually occurs on the chest or the back. In women, legs, neck, and face are the susceptible sites. The initial symptoms include a change in the appearance of an existing mole or the occurrence of a new, unusual looking mole. It may have an asymmetrical shape, irregular border, uneven distribution of pigment, and a diameter of more than six millimeters. The National Cancer Institute states that in 2017, about 87110 patients were expected to get detected with melanoma in the country, and approximately 9730 individuals would pass away fighting the disease.
Causes of melanoma
The exact cause of melanoma is still not known to scientists, but most of the findings suggest that a mutation in the melanocytes is the most likely reason behind this deadly disease. Under normal circumstances, the formation of skin cells takes place in an ordered and controlled manner. News cells arise from the division of melanocytes, which pushes old cells toward the outer edge of the epidermis, where they die and eventually get detached from the skin’s surface. In the case of melanoma, mutation (change in the DNA) occurs in some of the melanocytes, which results in uncontrolled production of abnormal melanocytes and forms a mass of cancerous cells on the skin.
Some specific factors may lead to the development of melanoma:
- Individuals having fair skin, light-colored eyes, and blond hair are more likely to get melanoma.
- Exposure to different types of UV rays increases the chances of developing melanoma.
- Individuals living close to the equator and exposed to direct sunrays throughout the year have a higher chance of contracting melanoma.
Types of melanoma
There are different kinds of melanoma depending on the growth of the melanocytes:
- Superficial spreading melanoma
It is the most common type of melanoma occurring on the arms, legs, chest, and back. In this case, cells grow slowly in the beginning and spread across the surface of the epidermis later.
- Nodular melanoma
It is the most aggressive and the second-most common type of melanoma occurring on the trunk, head, or neck. The pigment usually becomes red, with an increase in the size of the mole.
- Lentigo maligna melanoma
It is a less frequent and less dangerous type of melanoma that usually affects the older population. It initiates as Hutchinson’s freckle or lentigo maligna and progresses slowly over the years.
- Acral lentiginous melanoma
It is the most uncommon form of melanoma usually occurring on the hands, soles of feet, or below the nails. The incidence is more in dark-skinned people, and there is no link between exposure to the sun and the occurrence of this disease.
Melanoma is a severe type of malignancy as it has a higher probability of metastasizing and spreading to other organs, but recent developments in medical science have considerably improved the life expectancy of the patients.