Skin cancer happens when damage to the DNA inside skin cells is not repaired, causing abnormal cells to grow out of control. Most cutaneous cancers fall into three main types: basal cell carcinoma, squamous cell carcinoma, and melanoma (Source: American Cancer Society, 2023).

Clinicians group skin cancers as melanoma and non-melanoma skin cancers. Non-melanoma skin cancers are dominated by basal cell carcinoma (the most common type) and squamous cell carcinoma. Estimated proportions vary by region, but a commonly cited distribution is roughly: basal cell carcinoma ~80%, squamous cell carcinoma ~16%, and melanoma ~4% of diagnosed skin cancers (see sources for local statistics).

Quick overview — the three main types:

  • Basal cell carcinoma (BCC) — usually slow-growing, often appears on sun-exposed areas (face, nose).
  • Squamous cell carcinoma (SCC) — linked to cumulative sun or UV exposure; can be more aggressive and may spread to lymph nodes.
  • Melanoma — the least common but most dangerous type; arises from pigment-producing cells (melanocytes) and can spread quickly if not caught early.

This article explains how each type typically looks and behaves, how doctors diagnose them, current approaches to skin cancer treatment, and practical prevention steps. If you have a changing mole, a sore that won’t heal, or a new bump on sun-exposed skin, read on and consider scheduling a check with your doctor or dermatologist.

SQUAMOUS CELL CARCINOMA

What is squamous cell carcinoma?

Squamous cell carcinoma (SCC) is a common form of non-melanoma skin cancer that starts in the keratinocytes — the skin cells in the outermost layer (epidermis). It is typically related to cumulative ultraviolet (UV) exposure and is more likely to appear on sun-exposed areas such as the face, ears, scalp, neck, and hands.

What are the risk factors?

  • Sun and UV exposure — frequent sun exposure and tanning bed use significantly increase risk.
  • Fair skin, freckles, and tendency to burn rather than tan (higher risk in phototypes I–II).
  • Older age, although some high‑exposure occupations and outdoor sports increase risk in younger people (construction workers, farmers, surfers, etc.).
  • History of extensive ultraviolet therapy for skin conditions (e.g., psoriasis) or prior radiation to the area.
  • Chronic wounds, scars, ulcers, or sites of burns — long‑standing damage can develop into SCC.
  • Immunosuppression — people on immunosuppressive drugs (post‑transplant or for other diseases) have higher risk.
  • Exposure to certain carcinogens (for example, arsenic) and smoking (for some mucosal SCCs).

What does SCC look like — symptoms and signs?

SCC often begins as a firm, skin‑colored or red bump, a scaly patch, or a non‑healing sore. Common warning signs include:

  • A new growth or a sore that does not heal within 2–3 weeks.
  • A lesion that bleeds, crusts, or grows over time.
  • A wart‑like growth or a cratered ulcer in advanced lesions.
  • Rapid change in size or appearance, especially on the nose, lips, or ears (areas with rich blood supply).
  • A rare “vegetative” or verrucous form that can appear on soles or mucosal sites and may look cauliflower‑like.

Is early diagnosis possible?

Yes — when identified early, SCC is usually curable with local treatment. If left untreated for long periods, some SCCs can invade deeper tissues or spread to regional lymph nodes and, rarely, to distant organs.

How is SCC diagnosed?

Diagnosis is confirmed by a skin biopsy sent for pathological (histologic) examination. A clinician may perform an excisional or punch biopsy under local anesthesia to assess the tumor type, depth, and margins; these details guide staging and the treatment plan.

How is SCC treated?

Treatment depends on tumor size, depth, location, and patient health. Common options include:

  • Standard surgical excision: The lesion is removed with a margin of healthy tissue under local anesthesia. Good for most small‑to‑medium tumors; recovery time is short but depends on wound size.
  • Mohs micrographic surgery: Tissue‑sparing technique that removes the tumor layer by layer with immediate microscopic evaluation of margins. Preferred for high‑risk locations (face, lips, ears) and recurrent or large tumors — highest cure rates and maximal tissue preservation.
  • Electrocoagulation or curettage and cautery: May be used for small, low‑risk lesions; quicker but with variable cosmetic results.
  • Cryotherapy: Freezing small superficial lesions — office procedure, limited to select cases.
  • Radiation therapy: Useful when surgery is not feasible (certain large lesions, difficult locations, or medically unfit patients) or as adjuvant therapy for tumors with high risk of recurrence.
  • Lymph node management/systemic therapy: If there is clinical or imaging evidence of spread to lymph nodes or distant organs, lymph node removal, radiation, or systemic cancer treatment (including chemotherapy, targeted therapy, or immunotherapy in select advanced cases) may be indicated.

Pros/cons at a glance: surgical excision and Mohs give the best cure rates for localized SCC; radiation is an effective non-surgical alternative but may require multiple sessions and has different cosmetic outcomes; systemic treatments are reserved for advanced disease.

Prevention — how to reduce your risk

  • Limit UV exposure: seek shade, especially between 10:00 AM and 2:00 PM, and remember UV can reflect off surfaces.
  • Wear protective clothing, wide‑brim hats, and UV‑blocking sunglasses during outdoor activities.
  • Use a broad‑spectrum sunscreen (UVA and UVB protection) daily on exposed skin — many dermatology guidelines recommend SPF 30 or higher; sunscreen supplements, but does not replace shade and clothing.
  • Avoid tanning beds and deliberate tanning.
  • Practice regular skin self‑checks and photograph suspicious lesions for comparison; see a doctor if a sore doesn’t heal in 2–3 weeks or if a lesion changes, bleeds, or grows.

If you notice a new, changing, or non‑healing lesion — especially on sun‑exposed areas or in people with prior radiation or immunosuppression — consult your primary care physician or a dermatologist promptly. Early diagnosis leads to simpler treatment and better outcomes.

BASAL CELL CARCINOMA

Definition

Basal cell carcinoma (BCC) is the most common form of skin cancer and one of the most frequently diagnosed tumors in humans. It arises from basal cells in the lowest layer of the epidermis and is seen most often in people with fair skin. Risk increases with age, and BCC is especially common in older adults, though it can also occur in younger people—rarely as part of hereditary syndromes such as Basal Cell Nevus (Gorlin) syndrome.

Risk factors

  • Ultraviolet (UV) radiation — lifetime sun exposure, sunburns, and tanning bed use are primary environmental risks.
  • Ionizing radiation exposure — prior therapeutic radiation increases risk, especially in genetically predisposed individuals.
  • Genetic predisposition — familial syndromes (e.g., Basal Cell Nevus/Gorlin syndrome) raise lifetime risk.
  • Chronic skin damage and certain chronic skin diseases; long‑term exposure to carcinogens such as inorganic arsenic.
  • Immunosuppression — people on immunosuppressive medications or with compromised immune systems are at higher risk.

Typical presentation — symptoms and signs

BCC most often appears on sun‑exposed areas, particularly the face (commonly the nose and central facial zone). Early lesions may look like:

  • A small, pearly, skin‑colored or slightly pink bump (often 2–4 mm initially).
  • A translucent nodule with visible tiny blood vessels (telangiectasias).
  • A flat, scaly, or crusted patch that slowly enlarges.
  • An ulcerated lesion with rolled borders in more advanced cases.

BCC can present in several subtypes — nodular, superficial, cystic, pigmented, sclerosing (morpheaform), and others — which affects appearance and treatment approach. Because growth is usually slow, patients may delay seeking care; however, any persistent or changing lesion on the face or other sun‑exposed areas should prompt evaluation.

Is early diagnosis possible?

Yes — with specialist examination and dermoscopy, many BCCs are detected early when simple treatments are effective. Early detection generally leads to less extensive surgery and better cosmetic outcomes.

Diagnosis

Dermatologic assessment with dermoscopy helps identify suspicious lesions. Definitive diagnosis is made by biopsy (shave, punch, or excisional) and histopathology; the sample determines subtype and depth, which guide treatment decisions.

Treatment options

Treatment choice depends on tumor subtype, size, location, patient preference, and need for tissue conservation. Common approaches include:

  • Surgical excision: Standard treatment for many BCCs; removes the tumor with a margin of healthy tissue and provides pathology confirmation.
  • Mohs micrographic surgery: Tissue‑sparing, layer‑by‑layer removal with immediate margin assessment — preferred for high‑risk locations (central face), recurrent tumors, or lesions with aggressive histology.
  • Topical therapies: Imiquimod or 5‑fluorouracil can be used for selected superficial BCCs in low‑risk locations (discuss indications with a dermatologist).
  • Cryotherapy, photodynamic therapy, and laser: Options for small or superficial lesions when surgery is not ideal.
  • Radiation therapy: Alternative for patients who cannot undergo surgery or for lesions in anatomically difficult areas; may be used as adjuvant therapy in select cases.
  • Systemic therapy: For locally advanced or metastatic BCC not amenable to surgery or radiation, targeted agents (e.g., hedgehog pathway inhibitors) are available — managed by specialists.

When to prefer Mohs: choose Mohs surgery for facial lesions where preserving healthy tissue and optimizing cosmetic and functional results are priorities. For small superficial BCCs in low‑risk sites, less invasive options may be reasonable.

Prognosis and recurrence

BCC rarely spreads (metastasizes) but can invade locally and recur, particularly if incompletely excised. Long‑term follow‑up and sun‑protection measures reduce the risk of new tumors.

Prevention

  • Sun protection: use broad‑spectrum sunscreen (UVA/UVB), protective clothing, and hats; avoid tanning beds.
  • Regular skin checks: perform monthly self‑exams and see a dermatologist for suspicious changes or if you have a history of skin cancer.
  • Protect previously irradiated skin and manage chronic wounds promptly to reduce malignant transformation risk.

Example: a 65‑year‑old with a slowly enlarging pearly bump on the nose—early biopsy and Mohs surgery can remove the tumor with excellent cure rates and minimal tissue loss. If you notice a pearly or persistent lesion on the face or other skin areas, consult a dermatologist for evaluation.

MELANOMA

Definition

Melanoma is a malignant tumor that develops from melanocytes — the pigment‑producing cells in the skin. Although less common than basal cell or squamous cell carcinoma, melanoma is the most aggressive form of skin cancer because it can spread (metastasize) to lymph nodes and internal organs if not caught early.

Epidemiology varies by region and population, but cutaneous melanoma represents a small proportion of all skin cancers while accounting for a disproportionate share of skin‑cancer deaths. Incidence has increased partly due to improved awareness and diagnostic techniques like dermoscopy.

Risk factors

  • Sun and UV exposure — intermittent intense sun exposure and sunburns (especially in childhood) and tanning bed use increase melanoma risk.
  • Phenotype — fair skin, light eyes, red or blond hair, freckles, and a tendency to burn (phototypes I–II) raise risk.
  • Many or atypical moles (nevi) — a high number of nevi or dysplastic nevi increases likelihood of developing melanoma.
  • Family history and genetics — a first‑degree relative with melanoma notably increases risk; some hereditary syndromes markedly raise lifetime risk.
  • Immunosuppression — organ transplant recipients and people with immune deficiencies have higher rates.
  • Other factors — certain behavioral (frequent vacations in sunny climates), body factors (higher surface area exposure), and possibly hormonal influences in some populations.

Clinical types and what to look for

Melanoma presents in several clinical subtypes; presentations and typical locations differ:

  • Superficial spreading melanoma: Often arises from existing moles; watch for asymmetry, color changes, and irregular borders.
  • Nodular melanoma: Frequently appears as a rapidly growing, dome‑shaped nodule that may be dark or amelanotic (pale); can occur on the trunk or head/neck.
  • Acral lentiginous melanoma: Occurs on palms, soles, and under nails — look for a dark streak under the nail (Hutchinson’s sign) or pigmented patches on soles.
  • Lentigo maligna melanoma: Typically develops in chronically sun‑damaged skin of older adults (face, ears) as a large, irregularly pigmented patch.

Early detection — ABCDE and dermoscopy

Use the ABCDE rule to spot suspicious moles: Asymmetry, Border irregularity, Color variegation, Diameter >5 mm (or any new growth), and Evolution (rapid change). Dermoscopy by a trained clinician improves early diagnostic accuracy.

Diagnosis and staging

Definitive diagnosis requires histopathologic examination after excisional biopsy when possible. Staging follows AJCC criteria, which incorporate tumor thickness (Breslow depth), ulceration, lymph node involvement, and distant metastasis. Sentinel lymph node biopsy can detect early regional spread in selected intermediate‑thickness melanomas.

Prognosis by stage (note: confirm with current AJCC and institutional data)

Prognosis depends primarily on vertical tumor thickness and stage at diagnosis — thinner, in‑situ melanomas have excellent outcomes, while survival decreases with greater depth and nodal or distant spread. (Specific 5‑year survival estimates should be updated from the latest AJCC or national cancer statistics.)

Treatment overview

Early‑stage melanoma is primarily treated surgically with wide local excision using margins based on Breslow thickness. For intermediate‑thickness or higher tumors, sentinel lymph node biopsy is often considered. In advanced or metastatic disease, modern systemic cancer treatments have improved outcomes and include:

  • Immunotherapy — checkpoint inhibitors (e.g., anti‑PD‑1 agents) are standard for many advanced melanomas and as adjuvant therapy in some settings.
  • Targeted therapy — for tumors with BRAF mutations, BRAF and MEK inhibitors can be effective.
  • Radiation and chemotherapy — used selectively for symptom control or in specific clinical scenarios; chemotherapy is less commonly the first line in modern practice.

Discuss options with a multidisciplinary team (dermatologic surgeon, medical oncologist, radiation oncologist) — staging and molecular testing (e.g., BRAF) guide systemic therapy choices.

Prevention and follow-up

  • Sun protection: regular use of broad‑spectrum sunscreen (UVA/UVB), protective clothing, and shade; avoid tanning beds.
  • Skin surveillance: monthly self‑checks and regular dermatology visits with dermoscopy for high‑risk people (family history, many nevi).
  • If you notice a changing mole or a new lesion that meets ABCDE criteria, photograph it and see a dermatologist promptly.

Key patient takeaway: melanoma can be highly treatable when detected early — know your moles, protect your skin from excess sun and tanning beds, and seek evaluation for any changing lesion.

CONCLUSION & NEXT STEPS

Skin cancer includes several types — basal cell carcinoma, squamous cell carcinoma, and melanoma — each with different risks, appearances, and treatment approaches. Early detection and sun‑protection are the most effective ways to reduce harm: most non‑melanoma skin cancers are curable with local treatment when found early, and melanoma outcomes are dramatically better when diagnosed at an early stage. If you are concerned about a suspicious mole or a sore that bleeds or does not heal, prompt evaluation by a doctor or dermatologist can make a major difference in treatment options and prognosis.

  • Top prevention steps: use a broad‑spectrum sunscreen (SPF 30+), wear protective clothing and wide‑brim hats, and avoid tanning beds.
  • Self‑care and surveillance: perform monthly skin self‑checks, photograph changing lesions, and keep regular dermatology follow‑ups if you are high risk (many moles, family history, prior radiation or immunosuppression).
  • When to seek care: see a clinician for any lesion that changes in appearance, grows, bleeds, crusts, or does not heal in 2–3 weeks — especially on the face, scalp, neck, or other sun‑exposed areas.

If you need help finding a specialist or scheduling an appointment, visit your primary care provider for a referral or use the clinic contact/appointment page on this site (suggest linking to your clinic or booking page). For quick answers, check the FAQ on what to expect at biopsy and a practical sunscreen guide. Remember: early action, consistent prevention, and informed care reduce the chance of advanced disease and simplify treatment — whether that means a minor excision for basal cell carcinoma or more involved care for melanoma.

  • If you only remember one thing:Protect your skin from excess sun and skip tanning beds.
  • Watch your moles — note any changes (ABCDE) and seek evaluation.
  • See a doctor early — early diagnosis often means simpler skin cancer treatment and better outcomes.