Healthcare professionals advise people to check for signs of skin cancer regularly throughout the year. Early detection improves the outlook of each type of skin cancer.

Skin cancer is the most common cancer in the United States. Melanoma is the most dangerous type, and it is less common than other forms of skin cancer.

In this article, we will describe the symptoms of the most common types of skin cancer and explain how to check the skin. We will also investigate prevention, causes, and risk factors, as well as diagnosis and treatments.

Symptoms and warning signs

Basal cell and squamous cell carcinoma are two examples of nonmelanoma skin cancer.

The U.S-based Skin Cancer Foundation says that everyone should examine their whole body, from head to toe, once a month, and take note of:

  • any new moles or growths
  • moles or growths that have grown
  • moles or growths that have changed significantly in another way
  • lesions that change, itch, bleed or have not healed

The most common sign of skin cancer is an abnormal pink or brown spot, patch, or mole.

There are different forms of skin cancer, and the most common are:

  • basal cell carcinoma
  • squamous cell carcinoma
  • melanoma

Melanoma is the type most likely to develop in a mole.

Enlarged lymph nodes can also signal skin cancer. Lymph nodes are small, bean-sized collections of immune cells beneath the skin. Many are in the neck, groin, and underarms.

How to spot basal and squamous cell skin cancers

Basal and squamous cell skin cancers are more common and not as dangerous as melanoma. They can develop anywhere, but they are most likely to form on the face, head, or neck.

A basal cell carcinoma may look like:

  • a flat, firm, pale or yellow area of skin, similar to a scar
  • a reddish, raised, sometimes itchy patch of skin
  • small shiny, pearly, pink or red translucent bumps, which can have blue, brown, or black areas.
  • pink growths that have raised edges and a lower center, and abnormal blood vessels may spread from the growth like the spokes of a wheel
  • open sores that may ooze or crust, and either do not heal or heal and return

A squamous cell carcinoma may look like:

  • a rough or scaly red patch that may crust or bleed
  • a raised growth or lump, sometimes with a lower center
  • open sores that may ooze or crust, and either do not heal or heal and return
  • a growth that looks like a wart

Not all skin cancers look alike. The American Cancer Society recommend that a person should contact a doctor if they notice:

  • a mark that does not look like others on the body
  • a sore that does not heal
  • redness or new swelling outside the border of a mole
  • itching, pain, or tenderness in a mole
  • oozing, scaliness, or bleeding in a mole

How to spot melanoma

The medical community has developed two ways to spot the early signs of melanoma, the most dangerous type of skin cancer.

A person can use the ABCDE method and the ugly duckling method.

1. The ABCDE method

Brown spots, marks, and moles are usually harmless. However, the first sign of melanoma can occur in what doctors call an atypical mole, or dysplastic nevi. To spot an atypical mole, check for the following:

  • A: Asymmetry. If the two halves of a mole do not match, this can be an early indication of melanoma.
  • B: Border. The edges of a harmless mole are even and smooth. If a mole has uneven edges, this can be an early sign of melanoma. The mole’s border may be scalloped or notched.
  • C: Color.Harmless moles are a single shade, usually of brown. Melanoma can cause differentiation in shade, from tan, brown, or black to red, blue, or white.
  • D: Diameter. Harmless moles tend to be smaller than dangerous ones, which are usually larger than a pencil’s eraser — around one-quarter of an inch, or 6 millimeters.
  • E: Evolving. If a mole starts to change, or evolve, this can be a warning. Changes may involve shape, color, or elevation from the skin. Or, a mole may start to bleed, itch, or crust.
ABCDE method for spotting melanoma

2. The ugly duckling method

The ugly duckling method works on the premise that a person’s moles tend to resemble one another. If one mole stands out in any way, it may be a sign of skin cancer.

Of course, not all moles and growths are cancerous. However, if a person notices any of the above characteristics, they should speak to a healthcare professional.

How to diagnose skin cancer

Doctor checking a patients mole
A doctor or a dermatologist can diagnose skin cancer.

First, a doctor will examine the skin and take a medical history.

They will usually ask when the mark first appeared, if its appearance has changed, if it is ever painful or itchy, and if it bleeds.

The doctor will also ask about a person’s family history, and any other risk factors, such as lifetime sun exposure.

They may also check the rest of the body for other atypical moles and spots. Finally, they may feel the lymph nodes to determine if they are enlarged.

The doctor may refer a person to a dermatologist, a skin doctor, who may:

  • examine the mark with a dermatoscope, a handheld magnifying device
  • take a small sample of skin, a biopsy, and send it to a lab to check for signs of cancer

Causes and risk factors

Researchers do not know why certain cells become cancerous. However, they have identified risk factors for skin cancer.

The most important risk factor for melanoma is exposure to ultraviolet (UV) rays. These damage the skin cells’ DNA, which controls how the cells grow, divide, and stay alive.

Most UV rays come from sunlight, but they also come from tanning beds.

Other risk factors include:

  • Moles – A person with more than 100 moles is more likely to develop melanoma.
  • Fair skin, light hair, and freckles – The risk of developing melanoma is higher among people with light skin. Those who burn easily have an increased risk.
  • Family history – Around 10 percent of people with the disease have a family history of it.
  • Personal history – Melanoma is likelier to form in a person who has already had it. People who have had basal or squamous cell cancers also have an increased risk of developing melanoma.

Preventing skin cancer

The best way to reduce the risk of skin cancer is to limit exposure to UV rays. A person can do this by using sunscreen, seeking shade, and covering up when outdoors.

Anyone wishing to prevent skin cancer should also avoid tanning beds and sunlamps.

Noncancerous skin growths

It can be easy to mistake benign growths for skin cancer. The following skin conditions have similar symptoms to skin cancer:

  • Seborrheic keratosis: brown, black, or tan growths that appear in older adults.
  • Cherry angioma or hemangioma: small growths, made up of blood vessels, that are typically red but may rupture and turn brown or black.
  • Freckles: flat, darker areas of skin that appear after the skin is exposed to UV light.
  • Dermatofibroma: small, firm, round bumps that form under the skin and may change color over time.
  • Skin tags: harmless, soft growths.

Treatment

woman receiving radiation therapy for cancer
Radiation therapy is an alternative treatment for skin cancer.

A doctor usually removes basal cell and squamous cell cancers with minor surgery.

Radiation therapy is an alternative treatment when a person cannot undergo surgery. A doctor may also recommend this treatment when the cancer is in a place that would make surgery difficult, such as on the eyelids, nose, or ears.

For melanoma, the best treatment will depend on the stage and location of the cancer. If a doctor diagnoses melanoma early, they can usually remove it with minor surgery.

In some cases, doctors may suggest other types of surgery or radiation therapy.

Summary

Healthcare professionals advise people to check for symptoms of skin cancer regularly.

The most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma. Receiving a diagnosis early will improve the outlook, regardless of the type.

If a mole or mark has undefined or uneven edges, multiple colors, or is atypical in any way, this can indicate skin cancer, as can the appearance of sores that do not heal. Anyone with concerns about marks, moles, or lesions should speak to a doctor.

Exposure to UV light is the most significant risk factor for skin cancer. The best way to prevent the disease is to stay safe in the sun.