Skin Cancer is the most common form of cancer. More than 3.5 million skin cancer cases are diagnosed annually in U.S. alone. Skin cancer develops in skin tissues. In skin cancer, cells in skin tissues abnormally start growing and multiply without control. This leads to changes in the cells. The mass developed due to multiple growths of cells is known as tumors or lesions. The spread of tumor or cancerous cells is known as metastasis. Tumors interfere with tissues surrounding it and prevent them from getting the oxygen and nutrients. This affects functioning of these tissues.

Skin cancer starts with pre-cancerous lesions. There are tumors or lesions which are not cancerous, when they start but can turn into malignant or cancerous tumors with time. These changes are known as dysplasia. A patch of red or brown, scaly, rough skin, known as Actinic Keratosis can change into squamous cell carcinoma over time. There are some abnormal moles also, which can turn into melanoma with time. They are nevus and dysplastic nevi. Moles are simple and common growths on the skin and rarely change into skin cancer.

Dysplastic nevi are moles, which can turn into cancer with time. It may be more than a 100 on a patient’s body. Dysplastic nevi can turn into Melanoma within an existing nevus or on an area of skin. These moles are irregularly shaped with fading borders. They are large moles of mixed color. They may be in a mix of pink, red, tan, and brown color. The most common cause of skin cancer is over exposure of sun or Ultra Violet Rays. Best way to prevent skin cancer is to avoid over exposure to sun.

Types of skin cancer

Skin cancer may be of various types. Some skin cancers, which develop in melanocytes or pigment making cells, are known as melanoma. Some skin cancer known as basal cell carcinoma develop in the lower part of the epidermis. Skin cancer developing in squamous cells on the surface of the skin is known as squamous cell carcinoma. Skin cancer forming in neuroendocrine cells is known as neuroendocrine carcinoma of the skin. Skin cancers are majorly of three types- Basal Cell Carcinoma, Squamous Cell Carcinoma and Melanoma. Most of the skin cancers are either Basal Cell Carcinoma or Squamous Cell Carcinoma.

Basal Cell Carcinoma

Basal Cell Carcinoma is the most common type of skin cancer. These cancerous cells or carcinomas usually develop on the face, neck, and hands of the patient. It normally does not spread to the other part of body and can be easily treated. Most common symptoms of this disease are bleeding or oozing sores, irritation and redness of an area of skin, yellow or white scar like patches or a pink or pearl like bump on the skin.

Squamous Cell Carcinoma

Squamous cell carcinoma is the other common type of skin cancer after basal cell carcinoma. It usually develops on the part of skin, which is widely exposed to the sun. It generally forms on the ears, the face and the mouth of the patient but is capable of spreading to any part of the body. Its symptoms are a bump turning in to an open sore such as ulceration, reddish, flat crusty spot, and large bumps and not healing sores. If it is not treated, it quickly spreads to other parts of body and affects lymph, blood and nerves.


Melanoma is considered as the most dangerous skin cancer. It can start in any part of the patient’s body. It commonly affects the arms, legs and trunk. It can be treated if detected at early stages. Its symptoms are a mole, freckle, or spot that changes color, size and shape.

Merkel cell carcinoma

Merkel cell carcinoma is a very rare type of skin cancer. Merkel cells are located in the top layer of skin and near to nerve endings. They can affect nerves that receive the sensation of touch. Merkel cells are found in the layer of basal cells at the deepest part of the epidermis and acts as connectors for nerves

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