Squamous cell carcinoma: information for patients

Squamous cell carcinoma, also called epidermoid carcinoma , is a common type of skin cancer. In this article, we refer to cutaneous squamous cell carcinoma , that is, the type that appears on the skin or in transitional areas such as the lips. It may appear as a scab, a wound that won’t heal, a rough plaque, or a firm lump. Most cases are successfully treated when detected early, but it’s important not to underestimate the risk: some tumors can grow, recur, or spread, especially if there are risk factors.

Summary in 60 seconds

• Cutaneous squamous cell carcinoma is a cancer that originates in cells of the superficial layer of the skin called the epidermis.
• It usually appears in areas with accumulated sun exposure: face, ears, scalp, lips, neck, back of hands, forearms and legs.
• It may appear as a rough plaque, a persistent scab, a wound that bleeds or does not heal, a wart-like lesion, or a hard lump.
• Ultraviolet radiation from the sun and tanning beds is an important factor, although it is not the only one.
• It can also appear in scars, old burns, chronic wounds, or in immunosuppressed patients.
• Not every rough lesion is cancer, but a lesion that changes, hurts, bleeds, or does not heal should be evaluated by a dermatologist.
• The diagnosis is confirmed by clinical examination and, when appropriate, skin biopsy.
• The most common treatment is surgical, although there are alternatives depending on size, location, depth and risk.
• Early detection allows for more conservative treatments and better results.
• After squamous cell carcinoma, dermatological follow-up and photoprotection are part of long-term care.

What is squamous cell carcinoma?

Cutaneous squamous cell carcinoma is a malignant tumor that originates in keratinocytes , cells that make up much of the epidermis. It can appear as a localized lesion in the superficial layer of the skin or grow into deeper layers.

When it is confined to the outermost layer (epidermis), it is called squamous cell carcinoma in situ or Bowen’s disease . When it crosses this barrier and penetrates deeper, it is considered invasive squamous cell carcinoma . This distinction cannot be reliably established by appearance alone: biopsy and microscopic examination are necessary for a precise definition. AAD 2026

In general, the prognosis is favorable when detected and treated in early stages. European guidelines describe 5-year cure rates exceeding 90% after treatment, although individual risk depends on location, size, depth, microscopic differentiation, immune status, and other factors. Stratigos 2023

A wound that does not heal should not be normalized: in skin, persistence is a clinical fact.

Why does it appear?

The most widely recognized cause is cumulative damage from ultraviolet radiation , especially in people with years of sun exposure or use of tanning beds. The risk increases when the skin has received a lot of sun throughout life, even if the sunburns occurred years ago. CDC 2026

Other factors also play a role:

• Fair skin, light eyes, history of sunburns or tendency to burn easily.
• Advanced age, due to accumulated sun damage and changes in skin repair.
• Personal history of skin cancer or actinic keratosis.
• Immunosuppression, for example in transplant recipients or those undergoing certain treatments.
• Scars, old burns, ulcers, or wounds that remain open for a long time.
• Previous exposure to radiotherapy or arsenic.
• Some human papillomavirus infections in specific locations.

The NCI includes among its risk factors natural or artificial sun exposure, fair skin, personal or family history, chronic inflammation, immunosuppression, arsenic, and prior radiation therapy. NCI 2025

A common lesion related to sun damage is actinic keratosis . It is not the same as invasive carcinoma, but it can represent skin with precancerous damage and, in some cases, progress to squamous cell carcinoma. Therefore, persistent, multiple, or thick actinic keratoses should be evaluated.

What does it look like and what symptoms does it cause?

Squamous cell carcinoma can take many forms. There is no single, universal appearance. It may look like:

• A rough or scaly plaque that does not improve.
• A scab that reappears after falling off.
• A wound that does not heal or that bleeds easily.
• A firm, pink, reddish, brown, or skin-colored lump.
• A lesion that resembles a wart, but grows or changes.
• A raised area over an old scar or burn.
• A painful, sensitive injury with itching, burning, tingling, or numbness.

The American Cancer Society describes squamous cell carcinomas as commonly occurring in sun-exposed areas such as the face, ears, neck, lips, and backs of the hands, although they can also arise in the genitals, scars, or chronic wounds. ACS 2024

In darker skin tones, squamous cell carcinoma can also appear in areas with little sun exposure. This is important because a false sense of “low risk” can delay seeking medical advice. The AAD notes that people of all skin tones can develop it. AAD 2026

What can you do today?

The safest thing to do is to act with sound judgment, without alarmism and without unnecessary delay.

First, observe the lesion carefully: when it appeared, whether it grows, bleeds, hurts, ulcerates, scabs over, or returns after seemingly healing. A well-lit photograph taken every few weeks can help document changes, but it is not a substitute for medical evaluation.

Second, schedule a dermatology appointment if the lesion persists, changes, or concerns you. The AAD emphasizes that accurate diagnosis requires a skin examination, medical history, and biopsy when the dermatologist deems it necessary. AAD 2026

Third, protect your skin from the sun consistently: shade, long-sleeved clothing or fabrics with UV protection, a wide-brimmed hat, sunglasses, and broad-spectrum sunscreen. Protection should be maintained year-round, not just on vacation.

Fourth, avoid tanning beds. Artificial UV radiation also damages the DNA in skin cells and increases the risk of skin cancer. CDC 2026

Fifth, check the rest of your skin. Having had squamous cell carcinoma increases the need for surveillance because new lesions may appear, not necessarily of the same type.

What NOT to do?

Do not repeatedly pick at scabs or try to «burn» the lesion at home. This can irritate, infect, alter its appearance, and delay diagnosis.

Don’t treat it as a common wart without evaluation if it’s growing, bleeding, painful, or not healing. Some malignant lesions can resemble warts or harmless wounds.

Do not apply corticosteroids, antibiotics, acids, home remedies, or «natural» products for weeks without a diagnosis. Partial improvement of a lesion does not rule out skin cancer.

Don’t wait until it hurts. Many squamous cell carcinomas are asymptomatic in their early stages. The absence of pain does not mean it is harmless.

Don’t assume that a lesion on dark skin, genitals, nails, scars, or areas with little sun exposure «can’t be» squamous cell carcinoma. It may be less common, but it’s not impossible.

When should I consult?

Consult a dermatologist if you notice any of these signs:

• Injury that does not heal after several weeks.
• A wound that bleeds, forms a scab, and reopens.
• A rough, thickened, or scaly plaque that grows.
• A firm, painful or tender lump.
• A wart-like lesion that increases in size.
• New change over an old scar, burn, or ulcer.
• Injury to lip, ear, scalp, genitals, fingers or around/under a nail.
• Pain, tingling, numbness, or an electric sensation near the injury.
• Enlarged lymph nodes near the affected area.
• Rapid growth or spontaneous bleeding.

High-risk lesions or those suspected of spreading may require lymph node evaluation and imaging studies, such as ultrasound, CT, MRI, or PET, depending on the case. AAD 2026

What does a dermatologist usually do?

The dermatologist examines the lesion and may also check the entire skin. They will ask about a history of skin cancer, sun exposure, immunosuppressant treatments, transplants, previous radiation therapy, scars, chronic wounds, and recent changes.

Dermscopy , a magnifying and illuminating tool that allows the observation of structures not visible to the naked eye, is often used. Dermscopy can provide guidance but does not replace histological confirmation when histological examination is suspected. DermNet describes dermatoscopic patterns useful in squamous cell carcinoma, such as central keratin, white areas, white circles, and looped vessels; however, the definitive diagnosis depends on the clinical context and, frequently, on the biopsy. DermNet 2025

A skin biopsy involves taking a sample of the lesion under local anesthesia for microscopic analysis. The report can indicate whether it is squamous cell carcinoma, whether it is in situ or invasive, how deep it extends, whether the margins are involved, and if there are any other risk factors.

Treatment is chosen based on location, size, depth, subtype, immune status, function of the affected area, and the patient’s realistic expectations. Options may include:

• Surgical excision with safety margin.
• Mohs micrographic surgery, especially in areas where it is advisable to preserve tissue or in higher risk tumors.
• Curettage and electrodesiccation in selected low-risk lesions.
• Radiotherapy when surgery is not appropriate or as part of a more complex plan.
• Topical or photodynamic treatments in specific situations, especially in very superficial lesions or field damage, not as a universal substitute for surgery.
• Immunotherapy or other systemic treatments in advanced disease, when it is not possible to cure with surgery or radiotherapy.

Frequently Asked Questions

Is squamous cell carcinoma the same as melanoma?

• No. They are different types of skin cancer. Squamous cell carcinoma originates in keratinocytes; melanoma originates in melanocytes. One does not «turn into» the other, although a person who has had skin cancer may have a higher risk of developing other types in the future. AAD 2026

Does squamous cell carcinoma always spread?

• No. Many cases are cured with local treatment when detected early. However, some squamous cell carcinomas have a higher risk of recurrence or spread, especially if they are large, deep, poorly differentiated, occur in certain areas, or affect immunocompromised individuals. Alam 2018

Can it hurt?

• Yes, it can hurt, itch, burn, or cause tenderness, but it can also be completely painless. That’s why you shouldn’t wait until you feel pain to seek medical advice.

How can I tell if it’s a normal scab or something to worry about?

• A scab from a common wound should gradually improve. A scab that returns, bleeds, thickens, grows, or doesn’t heal warrants further evaluation. Duration, change, and recurrence are important indicators.

Can a biopsy «activate» cancer?

• No. A biopsy does not cause cancer. It is a diagnostic tool to determine the type of lesion and how to treat it. Delaying a biopsy when it is indicated is usually riskier than performing it.

Does it leave a scar after treatment?

• Scarring may occur, especially if surgery is required. The goal is to balance oncological safety, function, and aesthetic outcome. In delicate areas such as the face, lips, ears, eyelids, fingers, or genitals, the dermatologist may suggest techniques to preserve more tissue when appropriate.

After treatment, should I no longer worry?

• The treatment resolves the treated lesion, but does not eliminate the risk of new lesions. Follow-up, sun protection, and self-monitoring are part of ongoing care.

Bibliography and sources

• Kim JYS, Kozlow JH, Mittal B, Moyer J, Olenecki T, Rodgers P, et al. Guidelines of care for the management of cutaneous squamous cell carcinoma. J Am Acad Dermatol. 2018;78(3):560-578. doi:10.1016/j.jaad.2017.10.007.Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC6652228/
• Stratigos AJ, Garbe C, Dessinioti C, Lebbe C, van Akkooi ACJ, Bataille V, et al. European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma. Part 1: diagnoses and prevention—update 2023. Eur J Cancer. 2023;193:113251. doi:10.1016/j.ejca.2023.113251.Available at: https://pubmed.ncbi.nlm.nih.gov/37717283/
• Stratigos AJ, Garbe C, Dessinioti C, Lebbe C, van Akkooi ACJ, Bataille V, et al. European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma. Part 2: treatment—update 2023. Eur J Cancer. 2023;193:113252. doi:10.1016/j.ejca.2023.113252.Available at: https://pubmed.ncbi.nlm.nih.gov/37708630/
• Keohane SG, Botting J, Budny PG, Dolan OM, Fife K, Harwood CA, et al. British Association of Dermatologists guidelines for the management of people with cutaneous squamous cell carcinoma 2020. Br J Dermatol. 2021;184(3):401-414. doi:10.1111/bjd.19621.Available at: https://pubmed.ncbi.nlm.nih.gov/33150585/
• Queirolo P, Cinquini M, Argenziano G, Bassetto F, Bossi P, Boutros A, et al. Guidelines for the diagnosis and treatment of cutaneous squamous cell carcinoma: a GRADE approach for evidence evaluation and recommendations by the Italian Association of Medical Oncology. ESMO Open. 2024;9(5):103005. doi:10.1016/j.esmoop.2024.103005. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC11067535/
• Wysong A. Squamous-cell carcinoma of the skin. N Engl J Med. 2023;388(24):2262-2273. doi:10.1056/NEJMra2206348.Available at: https://pubmed.ncbi.nlm.nih.gov/37314707/
• Jiang R, Fritz M, Que SKT. Cutaneous squamous cell carcinoma: an updated review. Cancers (Basel). 2024;16(10):1800. doi:10.3390/cancers16101800. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC11119634/
• American Academy of Dermatology Association. Squamous cell carcinoma: from symptoms to treatments [Internet] . Rosemont: American Academy of Dermatology Association; 2026 [citado 2026 Jun 1] . Available at: https://www.aad.org/public/diseases/skin-cancer/squamous-cell-carcinoma
• National Cancer Institute. Skin Cancer Treatment (PDQ®)–Patient Version [Internet] . Bethesda: National Cancer Institute; 2025 [citado 2026 Jun 1] . Available at: https://www.cancer.gov/types/skin/patient/skin-treatment-pdq
• Centers for Disease Control and Prevention. Reducing Risk for Skin Cancer [Internet] . Atlanta: Centers for Disease Control and Prevention; 2026 [citado 2026 Jun 1] . Available at: https://www.cdc.gov/skin-cancer/prevention/index.html
• American Cancer Society. Basal and Squamous Cell Skin Cancer Symptoms [Internet] . Atlanta: American Cancer Society; 2024 [citado 2026 Jun 1] . Available at: https://www.cancer.org/cancer/types/basal-and-squamous-cell-skin-cancer/detection-diagnosis-staging/signs-and-symptoms.html
• DermNet. Cutaneous squamous cell carcinoma [Internet] . DermNet NZ; 2025 [citado 2026 Jun 1] . Available at: https://dermnetnz.org/topics/cutaneous-squamous-cell-carcinoma