Cancer is a life-threatening disease, and it is a disease whose prevalence is increasing rapidly throughout the world. It occurs when the normal healthy cells of the body begin to grow abnormally. Skin cancer is a type of cancer which occurs when the cells of the skin experience abnormal growth.
Skin is one of the essential organs of the body as it acts as a barrier that protects the body against infections, ultraviolet rays, and other toxic substances. It performs various vital functions. Primarily skin consists of two layers – the epidermis, and the dermis.
- The epidermis layer is the outermost layer of the skin which consists of a constellation of cells which are known as keratinocytes. The role of keratinocytes is to synthesize keratin which is involved in a protective role.
- The dermis layer is the middle layer of the skin which lies on the subcutaneous tissue and contains small lobes of fat cells which are known as lipocytes.
According to the researchers, the prevalence of skin cancer in people is increasing day by day and an excessive exposure to ultraviolet rays is said to be the most common cause of the development of skin cancer. Mainly, there are three types of skin cancer – basal cell carcinoma, squamous cell carcinoma, and melanoma.
Basal Cell Carcinoma
Basal cell carcinoma is the most common type of skin cancer and it belongs to non-melanoma type of skin cancer. Basal cell carcinoma develops in the basal cell layer of the epidermis and damage to DNA can be one of the causes of the development of basal cell carcinoma and an exposure to sunlight can lead to damage to DNA. Basal cell carcinoma is categorized into various types and some of them are as follows:
- Nodular basal cell carcinoma – It is the most common type of basal cell carcinoma and it usually occurs on the areas of head and neck.
- Cystic basal cell carcinoma – It is characterized by cystic nodules which appear as a dome-shaped and blue-grey in color.
- Cicatricial basal cell carcinoma – It is an aggressive type of basal cell carcinoma and it is characterized by the white sclerotic plaque.
- Infiltrative basal cell carcinoma – It is also an aggressive type of carcinoma and is characterized by the deep infiltration.
- Superficial basal cell carcinoma – This type of basal cell carcinoma usually occurs on the areas such as a trunk or distal extremities.
- Pigmented basal cell carcinoma – It is a common type of basal cell carcinoma and it looks like nodular basal cell carcinoma.
When the basal cell carcinoma is left untreated, it leads to the formation of ulcers and these ulcers are known as rodent ulcers.
Squamous Cell Carcinoma
Squamous cell carcinoma is the common non-melanoma skin cancer and this type of skin cancer develops in the upper layer of the epidermis and it most commonly appears on the part of the body that is most commonly exposed to the ultraviolet rays. Although it can occur on any part of the body, most often it occurs on areas like head, neck, and back of the hands. Squamous cell carcinoma appears as the scaly and crusty areas of the lump that sometimes bleed and can become inflamed. It is characterized as a thick, red and scaly spot which may also look like a sore that has not healed.
Squamous cell carcinoma can occur in anyone but people who are at the high risk of developing this type of cancer include builders, farmers and people who are often out to the sun. Also, people who have suppressed the immune system or people who have fair skin are at a higher risk of developing squamous cell carcinoma. An excessive exposure to sunlight is the most common cause of squamous cell carcinoma.
Melanoma is defined as a malignancy of the pigments producing cells, known as melanocytes. Melanomas are the malignant tumors that are derived from melanocytes and the skin is the most common site of involvement. Occasionally, it can also develop on other organs of the body such as eye, oral and nasal mucosa, vulval and anorectal mucosa, other gastrointestinal mucosa and the central nervous system. Melanoma can be divided into four subtypes – superficial spreading melanoma, lentigo maligna melanoma, nodular melanoma, acral lentiginous melanoma, and amelanotic melanoma.
- Superficial spreading melanoma – Superficial spreading melanoma is the most common type of melanoma and it usually characterized as an irregular pigmented macule.
- Lentigo Maligna – It is characterized by the slow growing patch of discolored skin with variegated shape and color.
- Acral lentiginous melanoma – It is a common form of melanoma and is often found in dark skin population. It is characterized by a slowly enlarging flat patch of discolored skin.
- Nodular melanoma – These are aggressive tumors that can occur at any site but most often it occur in the exposed areas of the head and neck. It appears as rapidly enlarging lumps.
- Amelanotic melanoma – It is difficult to clinically diagnose this type of melanoma and it is characterized by the pink nodules or patch that appears on the skin.
Tags: Melanoma, Basal cell carcinoma, Skin cancer symptoms