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What is the Difference Between Melanoma and Nonmelanoma Skin Cancer?

Nonmelanoma skin cancer can refer to any cancer that forms in the basal, squamous or Merkel cells of the skin. Melanoma is a cancer that develops in the skin’s melanocytes. Let’s take a closer look at these skin cancers and how they differ from one another.

Nonmelanoma skin cancer

There are multiple types of nonmelanoma skin cancer, but the main forms are basal cell carcinoma, squamous cell carcinoma and Merkel cell carcinoma.

Basal cell carcinoma

Basal cell carcinoma is the most common type of cancer, with more than four million cases diagnosed in the United States every year. This cancer forms in the basal cells – one of three types of cells that form the top layer of skin. Basal cell carcinoma can vary considerably in appearance, but may look like:

  • A waxy bump
  • A white or pink patch
  • An open sore
  • A scar
  • An elevated growth with rolled edges
  • A growth that crusts, itches, oozes or bleeds

It’s a good idea to speak with a dermatologist if you have any unusual changes in your skin. Basal cell carcinoma rarely spreads and is usually treated successfully, but delaying treatment can lead to complications.

Squamous cell carcinoma

Squamous cell carcinoma develops in the flat squamous cells near the surface of the skin. Unlike basal cell carcinoma, which usually forms on sun-exposed areas of the skin, squamous cell carcinoma may also develop around the genitals and other areas of the body that are not exposed to sunlight. It may appear as a:

  • Scaly red patch
  • Tough and thickened patch of skin
  • Wart
  • Raised growth with a depression

Squamous cell carcinoma is common and usually very treatable, but it is important to promptly seek care if you notice any abnormality on your skin. This type of skin cancer can spread and become very serious if treatment is delayed.

Merkel cell carcinoma

Merkel cell carcinoma is a rare and aggressive cancer. Forming in the Merkel cells deep within the top layer of the skin, this type of cancer often appears as a shiny pink, red or bluish lump that grows quickly.

Merkel cell carcinoma is serious, but with early detection, many cases can be treated successfully. Be sure to speak with a physician as soon as possible if you notice an unusual lump on your skin.

Melanoma skin cancer

Melanoma is a relatively common cancer that begins in the melanocytes, which are the pigment-producing cells located on the top layer of the skin. Damage caused by ultraviolet (UV) light from the sun and tanning beds can trigger cancerous changes in these cells, but melanoma may also develop in areas of the body that aren’t exposed to the sun. Make sure to speak with a dermatologist if you notice warning signs of melanoma, which may include a mole that:

  • Is a different shape, size or color from other moles on your body
  • Has multiple shades of tan, brown or black
  • Has an irregular border – not a perfect circle
  • Gradually changes color or shape

Melanoma is a very serious type of cancer, but early detection saves many lives. It’s always smart to have a suspicious-looking mole or growth checked out by a medical professional, even if it doesn’t perfectly match the descriptions in this article.

If you have been diagnosed with nonmelanoma skin cancer or melanoma, a skin cancer specialist at Moffitt Cancer Center can offer a second opinion after reviewing your lab work, biopsies and images. To learn more, fill out a new patient registration form or call 1-888-663-3488.