Causes

The primary cause of skin cancer is exposure to UV radiation from the sun or artificial sources such as tanning beds. UV radiation damages the DNA in skin cells, leading to mutations that can result in uncontrolled cell growth and the development of cancerous tumors. 

Other risk factors for skin cancer include:

1. Fair Skin: People with fair skin, light hair, and blue or green eyes are at higher risk of developing skin cancer because they have less melanin, the pigment that provides some protection against UV radiation.

2. History of Sunburns: A history of severe sunburns, particularly during childhood or adolescence, increases the risk of developing skin cancer later in life.

3. Family History: Individuals with a family history of skin cancer are at increased risk of developing the disease themselves.

4. Weakened Immune System: Immunosuppression, whether due to medical conditions such as HIV/AIDS or medications such as corticosteroids, can increase the risk of skin cancer.

Symptoms

The symptoms of skin cancer vary depending on the type of cancer but may include:

1. Changes in Skin Appearance: The development of new moles or changes in the size, shape, color, or texture of existing moles or skin lesions.

2. Persistent Sores: Sores that do not heal or that continuously ooze, crust, or bleed.

3. Irregular Borders: Skin lesions with irregular, jagged, or poorly defined borders.

4. Asymmetry: Skin lesions that are asymmetrical, with one half differing in appearance from the other half.

5. Itching or Pain: Skin lesions that itch, tingle, or cause discomfort or pain.

Diagnosis

Skin cancer is typically diagnosed through a combination of visual inspection, dermoscopy (skin examination using a specialized magnifying instrument), and biopsy (tissue sample analysis). 

During a skin examination, a healthcare provider will visually inspect the skin for any suspicious lesions or moles. 

Dermoscopy allows for a more detailed examination of skin lesions to assess their structure and pigmentation patterns. If a suspicious lesion is identified, a biopsy may be performed to remove a sample of tissue for analysis under a microscope to determine if cancer cells are present.

Treatment

The treatment of skin cancer depends on factors such as the type, size, location, and stage of the cancer, as well as the patient’s overall health and preferences. Treatment options may include:

1. Surgery: Surgical removal of the cancerous lesion is often the primary treatment for skin cancer. This may involve excisional surgery to remove the tumor and surrounding tissue, Mohs micrographic surgery for precise removal of cancerous cells while preserving healthy tissue, or curettage and electrodessication to scrape away the lesion and cauterize the wound.

2. Radiation Therapy: Radiation therapy uses high-energy beams to target and destroy cancer cells. It may be used as the primary treatment for small or early-stage skin cancers, or in combination with surgery for larger or more advanced cancers.

3. Topical Treatments: Topical medications such as chemotherapy creams or immunotherapy creams may be used to treat superficial skin cancers or precancerous lesions.

4. Cryotherapy: Cryotherapy involves freezing the cancerous lesion with liquid nitrogen to destroy the abnormal cells. It is often used for small, early-stage skin cancers or precancerous lesions.