5 Common Types of Skin Cancer and How to Recognize Them

Recognizing Skin Cancer

Skin cancer develops when cells in the skin grow abnormally. Ultraviolet (UV) radiation from sunlight or tanning devices can damage skin-cell DNA and contribute to this growth. Skin cancer is not one single disease: different types begin in different cells and can have distinct appearances.

A suspicious spot may look like a pearly bump, a rough or scaly patch, a changing mole, or a sore that does not heal. Some skin cancers can resemble harmless moles, scars, or other skin conditions, and they may appear on areas that receive little sun. Their appearance can also vary across skin tones.

The five types described below have different patterns, but appearance alone cannot confirm or rule out skin cancer. Ask a healthcare professional to assess a new, changing, bleeding, or persistent growth rather than trying to diagnose it yourself.

Skin Cancer Key Facts

1. Basal cell carcinoma (BCC) is the most common skin cancer; it usually grows slowly and rarely spreads, but can damage nearby tissue if untreated.
2. Squamous cell carcinoma (SCC) is the second most common skin cancer; it can grow at varying speeds and sometimes spread beyond the skin.
3. Melanoma is less common than BCC or SCC but is more likely to spread and can be life-threatening, particularly when advanced.
4. Merkel cell carcinoma is uncommon but can grow and spread quickly; a fast-growing or nonhealing bump warrants prompt medical assessment.
5. Sebaceous carcinoma often develops on an eyelid and may resemble a persistent stye or firm lump; appearance alone cannot identify it.
6. Warning signs include a new or changing spot, a sore that does not heal, repeated bleeding or crusting, and a growth that looks different from others.
7. The melanoma ABCDE guide highlights asymmetry, irregular borders, varied color, diameter often over about 6 millimeters, and evolution; smaller spots can still need evaluation.
8. A healthcare professional must assess suspicious lesions; a biopsy, when indicated, can confirm cancer and identify its type, while photographs cannot diagnose it.
9. Ultraviolet radiation from sunlight and indoor tanning can damage skin-cell DNA; protective clothing, shade, sunscreen, and avoiding indoor tanning can help reduce exposure.
10. Treatment depends on the cancer’s type, stage, size, and location and may include surgery, Mohs surgery, or other therapies; early assessment can inform care.

1. Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common type of skin cancer. It begins in basal cells in the epidermis, the skin’s outer layer. BCC usually grows slowly and rarely spreads beyond the skin, but it can grow deeper and damage nearby tissue if left untreated. The American Academy of Dermatology’s overview of skin cancer types describes its common patterns and locations.

A BCC may look like a shiny, pearly, translucent, or skin-colored bump. Other possible appearances include a pink, brown, or glossy black growth, a raised scaly patch, or a flat, pale, waxy area that resembles a scar. Some lesions have a rolled or raised edge, and small blood vessels may be visible.

The spot may bleed or crust, or look like a sore that does not heal or repeatedly returns. BCC often appears on sun-exposed areas such as the head, face, and neck, though it can develop elsewhere, including on skin usually covered by clothing. Mayo Clinic’s guide to basal cell carcinoma notes that its appearance can vary across skin tones.

On lighter skin, BCC may appear pink or skin-colored; on brown or Black skin, it may look brown or glossy black. These descriptions are warning signs, not a way to diagnose a spot. A clinician must assess a suspicious or changing lesion and determine whether further testing is needed.

2. Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) begins in squamous cells, which form much of the skin’s outer layer. It is the second most common type of skin cancer after basal cell carcinoma, and it can appear in a range of colors and shapes. The American Academy of Dermatology’s overview of SCC notes that a spot’s appearance alone cannot confirm a diagnosis.

Common signs include a rough, scaly patch, a firm or dome-shaped bump, a wart-like growth, or a sore that does not heal or returns. A lesion may crust or bleed and may be pink, red, brown, black, or skin-colored. These changes can occur across skin tones, so color alone does not rule out concern.

SCC often develops on the head, ears, lips, arms, and legs, but it can occur anywhere, including inside the mouth or on areas that receive little sunlight. People with darker skin may be more likely to develop it in less sun-exposed areas, which is one reason a skin check should not stop at the face and arms. A healthcare professional can assess the skin, including areas that receive little sunlight.

SCC may grow slowly or quickly. It can spread to nearby lymph nodes or other parts of the body, although spread is uncommon; untreated cancer can also damage surrounding tissue. Because a persistent or changing spot cannot be identified reliably by sight, arrange medical assessment rather than waiting for it to worsen. A healthcare professional can discuss treatment options and goals with the patient.

3. Melanoma

Melanoma begins in melanocytes, the cells that produce skin pigment. It is less common than basal cell or squamous cell carcinoma, but is more likely to spread and can be life-threatening. Early recognition matters, though appearance alone cannot confirm a diagnosis. The American Academy of Dermatology’s overview of skin cancer types explains that melanoma can be highly treatable when found early.

Melanoma may appear as a new dark spot or as a change in an existing mole. It can develop on skin that receives frequent sun exposure or on areas that rarely see the sun, and it can affect people of any skin tone. A full-skin check is therefore more useful than looking only at exposed areas.

The ABCDE guide describes common warning signs: asymmetry, when the two halves do not match; an irregular or blurry border; more than one color; a diameter often greater than about 6 millimeters; and evolution, meaning a change in size, shape, or color. The diameter is a guide, not a cutoff, because melanoma can be smaller. Evolution is especially important to notice. Mayo Clinic’s melanoma and skin cancer guidance also identifies changing moles as a warning sign.

A spot that looks different from a person’s other moles, or changes over time, should be assessed by a healthcare professional. A changing mole requires evaluation by a qualified medical professional rather than cosmetic treatment.

4. Merkel Cell Carcinoma

Merkel cell carcinoma is a less common but potentially fast-moving skin cancer. It often develops on the head or neck, though it can occur elsewhere, and may be mistaken for an ordinary sore. The American Academy of Dermatology’s overview of skin cancer types describes it as a cancer that can grow and spread quickly.

It may appear as a fast-growing bump, sore, or cyst that is red, pink, blue, or violet. The color and shape can vary, so appearance alone cannot establish whether a spot is cancer. A new growth that changes quickly or does not heal should be assessed by a healthcare professional.

Merkel cell carcinoma is most often diagnosed in White people aged 65 or older, but it can affect people of any skin tone. Its tendency to grow and spread quickly, and to return after treatment, makes prompt assessment especially important. A clinician can examine a suspicious area and determine whether further testing is needed.

A qualified medical professional must assess and diagnose suspected skin cancer, including when a concerning lesion is in a visible area.

5. Sebaceous Carcinoma

Sebaceous carcinoma is a less common skin cancer that often develops on an eyelid. It may look like a slowly growing stye or a painless, round, firm growth, so appearance alone cannot confirm what it is. The American Academy of Dermatology’s overview of skin cancer types notes that this cancer usually affects people aged 65 or older.

A persistent eyelid lump, or one that changes over time, deserves medical assessment, particularly if it does not behave like a typical stye. A clinician can examine the area and determine whether further testing is needed. Avoid trying to identify sebaceous carcinoma from photographs or appearance alone.

Sebaceous carcinoma can return after treatment, making appropriate diagnosis and follow-up important. A suspected skin cancer should first be assessed by a qualified medical professional.

Other Types and Shared Warning Signs

Basal cell carcinoma, squamous cell carcinoma, and melanoma are the three main types of skin cancer. Basal cell carcinoma is the most common and rarely spreads beyond the skin; squamous cell carcinoma can spread, though this is uncommon. Melanoma is more likely to spread and can be more dangerous. Merkel cell and sebaceous carcinomas are less common types, as described by the American Academy of Dermatology.

Another source describes dermatofibrosarcoma protuberans (DFSP), a slow-growing skin cancer that often begins as a firm, raised bump. It is another type, but is not among the five selected for this article.

Shared warning signs include a new growth or a change in an existing spot, mole, or patch. Look for changes in size, shape, or color, as well as sores that do not heal, bleed, or repeatedly crust. A spot that itches or looks different from others also deserves attention. Skin cancer may appear as a pearly bump, a rough or scaly patch, or a firm raised growth.

For melanoma, the ABCDE guide covers asymmetry, irregular borders, varied color, diameter often greater than about 6 millimeters, and evolution over time. A spot does not need to show every feature to warrant evaluation. The American Cancer Society’s image gallery notes that skin cancers can vary in appearance, and images cannot establish a diagnosis.

Skin cancer can resemble benign growths or other skin conditions, and different cancer types can look alike. A basal cell carcinoma may resemble a shiny bump, scaly patch, or nonhealing sore; squamous cell carcinoma may look like a rough patch or firm growth; and melanoma may resemble a mole. A healthcare professional should assess a persistent, changing, bleeding, or nonhealing spot.

Comparing Basal and Squamous Cell Risks

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are both linked to ultraviolet exposure, but they do not always behave alike. BCC usually grows slowly and rarely spreads, while SCC may grow slowly or quickly and can sometimes spread to lymph nodes or other organs. These are common patterns, not guarantees for an individual tumor; the American Academy of Dermatology’s overview of skin cancer types describes how growth and risk differ.

A lower chance of spread does not make BCC harmless. If untreated, either cancer can grow into nearby tissue and cause local damage. BCC may become more extensive and harder to treat, while SCC can also invade surrounding tissue and, less commonly, spread beyond the skin. A lesion’s features and a person’s health can affect its risk.

Prompt assessment matters even when a spot seems small or causes no discomfort. A persistent, changing, bleeding, or nonhealing lesion should be examined by a healthcare professional; appearance alone cannot confirm the diagnosis. A dermatologist can assess the area and, when needed, use a biopsy to identify the cancer type. For facial lesions, planning can also account for preserving healthy tissue.

Many skin cancers are highly treatable when found early, and BCC and SCC often can be cured. However, melanoma is more likely to spread and can become life-threatening when advanced. The outlook depends on the cancer type, its extent, and individual circumstances, so suspicious changes deserve timely medical evaluation.

Skin Cancer Diagnosis

A skin cancer diagnosis starts with an examination of the suspicious spot by a healthcare professional, often a dermatologist. The clinician may ask when it appeared and how it has changed, then review the rest of the skin rather than focusing only on the visible lesion. A full skin check can include areas that are easy to miss, such as the scalp, soles, and spaces between toes. Mayo Clinic’s overview of skin cancer describes this broader examination.

A photograph may help document a spot’s appearance and make later changes easier to compare. It is a record, not a diagnostic test, and should not replace an in-person assessment. The practice can discuss the patient’s concerns and treatment options.

When a spot needs further investigation, a clinician may take a biopsy. This involves removing a small tissue sample, or sometimes the entire lesion, so it can be examined under a microscope. A biopsy can confirm whether cancer is present and identify its type; appearance alone cannot provide that confirmation. The American Academy of Dermatology’s guidance on squamous cell carcinoma likewise identifies biopsy as the way to determine whether a suspicious spot is skin cancer.

Blood tests generally do not diagnose cutaneous squamous cell carcinoma. The assessment relies on examining the skin and, when indicated, testing tissue from a biopsy. If a spot is new, changing, persistent, or concerning, seek a professional evaluation rather than relying on photographs or blood tests.

Causes and Risk Factors

Skin cancer develops when damage to DNA disrupts the normal growth of skin cells. Ultraviolet (UV) radiation is a major cause: UV rays from sunlight and tanning beds or lamps can damage cell DNA and allow abnormal cells to grow. Both repeated exposure over time and intense exposure that causes sunburn can contribute, as described by the Cleveland Clinic.

Some factors raise the likelihood of skin cancer, including skin that burns easily, a history of blistering sunburns, and a personal or family history of the disease. A weakened immune system, whether related to an illness or medication, can also increase risk. These factors do not determine whether someone will develop cancer, and people of every skin tone can be affected.

Reducing UV exposure can help lower risk. Seek shade when sunlight is strongest, wear protective clothing, and use broad-spectrum sunscreen. Avoiding indoor tanning is another practical step. For more everyday prevention guidance, see ways to protect your skin from skin cancer.

Treatment Options

Skin cancer treatment is chosen according to the cancer’s type, stage, size, and location. A dermatologist or cancer specialist can explain the options after reviewing the diagnosis and the patient’s health needs. The Cleveland Clinic overview of skin cancer treatment describes several approaches, including surgery and therapies that target or destroy cancer cells.

Options may include excisional surgery, cryotherapy, curettage and electrodesiccation, chemotherapy, immunotherapy, radiation therapy, or photodynamic therapy. Some small, superficial cancers may be fully removed during a biopsy, while other cases need a separate treatment plan.

Mohs surgery removes cancerous tissue one thin layer at a time. Each layer is examined during the procedure, and more tissue is removed if cancer cells remain. This approach aims to preserve as much healthy skin as possible and is used for basal and squamous cell cancers, as well as some cancers near sensitive or cosmetically important areas such as the eyelids, ears, lips, and nose.

Treatment decisions can also account for the appearance and function of the affected area. Treatment planning can account for changes to the face after treatment. A qualified specialist can clarify the likely benefits, risks, and recovery involved in each option.

When to Seek an Assessment

Arrange a professional assessment for a new or changing spot, a lesion that bleeds or itches, or a sore that does not heal. Skin cancer can appear in many forms, and its appearance alone cannot confirm what a spot is. The American Cancer Society’s skin cancer image gallery also notes that examples cannot reliably identify or rule out cancer.

Check the whole skin surface, not only areas exposed to sunlight. Include the scalp, ears, palms, soles, spaces between toes, and other places that are difficult to see. A healthcare professional can assess the skin, including areas that are difficult to see.

Use mirrors or photographs to help notice changes over time, but do not rely on self-checks to diagnose a lesion. Early recognition and diagnosis matter, yet only a healthcare professional can determine whether a spot is skin cancer and whether further testing is needed.