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What Is Carcinoma?

Carcinoma is a type of cancer that starts in cells that make up the skin or the tissue lining organs, such as the liver or kidneys.

Like other types of cancer, carcinomas are abnormal cells that divide without control. They are able to spread to other parts of the body, but don't always. "Carcinoma in situ" stays in the cells where it started.

Not all cancers are carcinoma. Other types of cancer that aren't carcinomas invade the body in different ways. Those cancers begin in other types of tissue, such as:

  • Bone
  • Blood vessels
  • Immune system cells
  • Brain
  • Spinal cord

Types of Carcinoma

Although carcinomas can occur in many parts of the body, you may often hear people talk about these common types of carcinoma:

Basal cell carcinoma. This is the most common form of all cancers. It occurs in cells lining the deepest part of the skin's outer layer.

You should get quick treatment for basal cell carcinoma to avoid scars. But only in very rare cases does this type of carcinoma spread to other parts of the body.

Basal cell carcinomas often look like:

  • Open sores
  • Red patches
  • Pink growths
  • Shiny bumps or scars

If you have basal cell carcinoma it's likely that you got it because of too much time in the sun. You may have had a few bad sunburns or else spent a lot of time in the sun during your life.

Squamous cell carcinoma. Most people think of skin cancer when they hear the words "squamous cell carcinoma." And it is true that this type of carcinoma often shows up on the skin.

But squamous cell carcinoma can also be found in other parts of the body, such as cells lining:

  • Certain organs
  • Digestive tract
  • Respiratory tract

When squamous cell carcinoma develops in the skin, you often find it on areas that are exposed to the sun, such as the:

  • Face
  • Ears
  • Neck
  • Lips
  • Backs of the hands

Squamous cell carcinoma that develops on the skin is usually caused by spending too much time in the sun over the course of your life. This type of skin cancer tends to grow and spread more than basal cell cancers. In rare cases, it may spread to the lymph nodes. 

Squamous cell carcinomas may crust or bleed and can include:

  • Scaly red patches
  • Open sores
  • Growth with a depression in the middle
  • Warts

Renal cell carcinoma. This is the most common type of kidney cancer. It usually grows as a single tumor within the kidney.

Renal cell carcinoma is sometimes discovered when you have a CT scan or an ultrasound for another reason. Sometimes it is detected after it has already become very large or spread to other organs.

WebMD Medical Reference

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