Causes and Diagnoses

Causes and Diagnoses of Skin Cancer

The exact cause of skin cancer is unknown, but certain factors can increase your risk of developing these types of cancers. It is important to get regular skin screenings to detect skin cancer early.

Risk factors for basal cell and squamous cell skin cancer

  • Sun exposure: The sun's ultraviolet (UV) rays can damage your skin and lead to skin cancer. The more time you spend in the sun, the greater your chances are of getting skin cancer. This risk is even higher for people who live closer to the equator or who live at higher altitudes, where the sun's rays are stronger.
  • Use of tanning booths and sunlamps: These artificial sources of UV rays can also damage the skin, and the risk of cancer is especially high if they are used before age 30.
  • Certain colors of skin, hair and eyes: People with pale skin, red or blond hair, and green, blue or gray eyes have an increased risk of skin cancer. Having many freckles also increases your risk. However, people with darker skin can get skin cancer too.
  • Personal history of skin cancer or pre-cancer: People who have had skin cancer before are at increased risk of getting it in the future. The same is true of people who have had skin pre-cancer, such as actinic keratosis.
  • Older age: While skin cancer can occur at any age, the risk rises as people get older.
  • Being male: Men are more likely to get non-melanoma skin cancers than women.
  • Weakened immune system: People who have a weakened immune system, such as people who have had an organ transplant, are at higher risk of skin cancer. Their skin cancer is also more likely to be serious.
  • Exposure to arsenic: People who have been exposed to large amounts of arsenic have an increased risk of skin cancer.
  • Prior radiation treatment: People who have been treated with radiation therapy have a higher risk of skin cancer in the area that was treated.
  • Scars, burns or inflamed skin: Skin cancers are more likely to develop in areas of damaged skin.
  • Smoking: People who smoke are more likely to get skin cancer, especially on the lips.
  • Human papillomavirus (HPV) infection: Certain types of HPV can infect the skin in the genital area and increase the risk of skin cancer there.
  • Certain rare inherited conditions: People with a condition such as basal cell nevus syndrome (Gorlin syndrome) or xeroderma pigmentosum (XP) have a much higher risk of skin cancer, starting at an early age.

Risk factors for melanoma

Melanoma has similar risk factors, with important distinctions for gender, age and family history. Learn more about risk factors associated with melanoma.


Diagnosing skin cancer starts with a physical assessment of any lesions—bumps, spots or other marks on your skin that don't look normal—to determine their size, shape, color and texture.

During your exam, be sure to tell your physician if you’ve had skin cancer in the past, if you have a family history of skin cancer or if you have a history of blistering sunburns.

Your physician may take a biopsy of the lesion for further study.

Types of biopsies

  • Excisional biopsy: In this procedure, the entire lesion and part of the surrounding skin is removed with a scalpel. The wound is then closed with sutures, staples, steri-strips or surgical glue.
  • Incisional biopsy: In an incisional biopsy, only part of the lesion is removed.
  • Punch biopsy: Using a special tool, a short cylinder of tissue—like an apple core—is removed. The biopsy sample is removed and the edges of the wound are then stitched together.
  • Shave biopsy: Your physician will shave off the top layers of a lesion with a scalpel. Since part of the lesion can be left behind, you may need another procedure to completely remove it.

Your biopsy sample will be sent to a lab, where a pathologist will look at it under a microscope. If skin cancer is found, the pathologist will analyze the lesion to help determine the extent (stage) of the skin cancer. The stage helps determine your treatment.

Your physician will give you the results and talk with you about other tests or treatments that may be needed in the event that skin cancer is found.

How is cutaneous T-cell lymphoma diagnosed?

Patients with cutaneous lymphomas, the cause or risk factors of which are unknown, often suffer from intractable itchiness, skin pain, ulcers, and infections, which greatly impair quality of life at many levels including one's ability to sleep.

In addition to a medical history and physical examination, a physician may order a biopsy of a skin tumor or lymph node to confirm the diagnosis.

The lymph nodes, bone marrow, and blood may also be sampled to look for lymphoma cells to help determine the stage of the disease.