Basal and squamous skin cancers can be found early. As part of a routine check-up, your doctor will look at your skin carefully. You should also check you own skin once a month. This is best done in front of a full-length mirror. A hand-held mirror can be used for places that are hard to see. You should know the pattern of moles, freckles, and other marks on your skin so that you'll notice any changes. Be sure to show your doctor any area that concerns you.

Friends and family members can also help by telling one another about abnormal-looking areas of skin. The key warning signs are

• a new growth,
• a spot or bump that's getting larger,
• a sore that doesn't heal within 3 months.

If you or your doctor finds something that doesn't look normal, certain tests may be used to find out if it is cancer or something else. If it is skin cancer, other tests may be done to find out if it has spread to other places.

Signs and symptoms of basal and squamous cell skin cancer

Skin cancers often don't cause symptoms until they become quite large. Then they can bleed or even hurt.

Basal cell carcinomas often appear as flat, firm, pale areas or as small, raised, pink or red, translucent, shiny, waxy areas that may bleed after minor injury. You might see one or more abnormal blood vessels, a depressed area in the center, or blue, brown, or black areas. Large ones may have oozing or crusted spots.

Squamous cell cancer may appear as growing lumps, often with a rough surface, or as flat, reddish patches that grow slowly.

Both of these types of skin cancer may develop as a flat area showing only slight changes from normal skin.

If your doctor has any reason to suspect skin cancer, one or more tests will be used to find out if cancer is really present.

History and physical exam

After asking questions about your health and doing a physical exam, the doctor will ask you when the mark on your skin first appeared and whether it has changed in size or the way it looks.

The doctor will note the size, shape, color, and texture of the area in question, and whether there is bleeding or scaling. He or she may check the rest of your body for spots and moles that could be related to cancer. The doctor may also check nearby lymph nodes (the bean-shaped collections of immune system cells) to feel if they are larger or firmer than usual. This could mean the cancer has spread to the nodes.

If you see your regular doctor, you may be referred to a doctor called a dermatologist. This doctor has special training in skin diseases and will look at the area more closely. He or she may use a special magnifying lens (a dermatoscope) to see spots on the skin. Sometimes a thin layer of oil is used with this test. Pictures of the spot may be taken.

Skin biopsy

If the doctor thinks that an area might be skin cancer, a sample of skin will be taken from the area to be looked at under a microscope. This is called a skin biopsy. There are different ways to do a biopsy. The choice depends on the most likely type of skin cancer, where it is on the body, and the size of the area. Any biopsy is likely to leave a scar. Different biopsy methods leave different scars. Ask your doctor ahead of time about the type of biopsy you will have and what kind of scar it will leave.

Types of biopsies

Shave Biopsy

To do this biopsy the doctor numbs the skin and then "shaves" off the top layers of the skin with a surgical blade.

Punch biopsy

This method is used to remove a deeper sample of skin. The doctor uses a tool that looks like a tiny round cookie cutter. After skin is numbed, the doctor uses the tool to cut through all layers of the skin to remove the tissue sample.

Incisional and excisional biopsies

This biopsy is needed if the doctor needs to look at deeper layers of the skin. He or she will numb the skin and then use a knife to cut through the full thickness of the skin. A wedge of skin is removed and the edges of the wound are sewn back together. Incisional biopsy involves removing only part of the tumor. If the whole tumor is removed, it is called an excisional biopsy.

All skin biopsy samples are looked at under a microscope. The skin sample is sent to a doctor who has special training to look for skin diseases using tissue samples. This doctor is called a pathologist.

Lymph node biopsy

If the doctor feels the lymph nodes are too large or too firm a lymph node biopsy may be needed. This is done to find out whether the cancer has spread from the skin to nearby lymph nodes.

There are 2 ways to do a lymph node biopsy. In fine needle aspiration (FNA), a thin needle is used to remove very small pieces of tissue from a lymph node. This does not leave a scar. If the doctor suspects cancer in a lymph node that the FNA did not reveal, a surgical lymph node biopsy may be done. For this, the doctor removes the whole lymph node, leaving a small scar.