Skin cancer is the most common malignancy worldwide. In Turkey, as in many countries with high average UV exposure, its incidence has been rising steadily over recent decades. The encouraging news is that, when detected at an early stage, the most common skin cancers — basal cell carcinoma, squamous cell carcinoma and early-stage melanoma — are highly treatable. The challenge is recognition: many patients present late because they were unfamiliar with the warning signs or dismissed a concerning lesion as cosmetically trivial.
At Virtuana Clinic in Izmit/Kocaeli, awareness and early referral are central to our approach to skin health. This guide explains what to look for, when to act, and what professional screening involves.
The Three Main Types of Skin Cancer
Basal Cell Carcinoma (BCC)
The most common skin cancer, accounting for approximately 75–80% of all cases. BCC arises from basal keratinocytes in the epidermis and is almost always associated with cumulative UV exposure. It grows slowly and rarely metastasises, but can cause significant local tissue destruction if left untreated for years.
Characteristic appearance:
- Pearly or translucent papule or nodule, often with visible telangiectasia (fine surface blood vessels).
- May have a central depression or ulceration ("rodent ulcer").
- Can appear flesh-coloured, pink, or — in pigmented BCC — brown or black.
- Superficial subtype: red, scaly patch, easily confused with eczema or psoriasis.
- Most common on sun-exposed areas: face, scalp, ears, neck, shoulders.
Squamous Cell Carcinoma (SCC)
The second most common skin cancer. SCC arises from squamous keratinocytes and has a higher metastatic potential than BCC, particularly when located on the lip or ear. It is strongly associated with UV exposure, chronic wounds, HPV infection (in genital variants), and immunosuppression.
Characteristic appearance:
- Firm, red, scaly nodule or plaque, often with a rough, wart-like surface.
- May ulcerate and bleed; the ulcer typically has raised, indurated edges.
- Actinic keratosis (rough, scaly patch from UV damage) is a precursor lesion — approximately 5–10% progress to SCC if untreated.
- Most common on sun-exposed sites, especially the face, ears, dorsal hands and lower lip.
Melanoma
The least common but most dangerous skin cancer, arising from melanocytes. Melanoma accounts for approximately 1% of skin cancer cases but causes the majority of skin cancer deaths due to its metastatic potential. Early detection, however, is associated with 5-year survival rates exceeding 95%. Late-stage (stage IV) melanoma carries a far poorer prognosis.
Characteristic appearance: Highly variable — melanoma is sometimes called "the great imitator."
- Superficial spreading melanoma (most common): Flat or minimally raised lesion with irregular borders and variegated colour (shades of brown, black, red, white, blue within the same lesion).
- Nodular melanoma: Rapidly growing, raised, dark nodule — may bleed easily. Particularly dangerous due to fast growth rate.
- Lentigo maligna melanoma: Arises on chronically sun-damaged skin (typically the face in older adults); begins as a flat, slowly expanding brown patch (lentigo maligna).
- Acral lentiginous melanoma: Arises on palms, soles, or under nails — not related to UV exposure; occurs at equal rates across all skin types.
- Amelanotic melanoma: Lacks pigment; appears pink or flesh-coloured and is frequently misdiagnosed. High clinical suspicion required.
The ABCDE Rule: Your Self-Examination Guide
The ABCDE rule is the internationally recognised mnemonic for identifying suspicious pigmented lesions. Any lesion meeting one or more of these criteria warrants professional evaluation:
| Letter | Criterion | What to Look For |
|---|---|---|
| A | Asymmetry | If you fold the lesion in half mentally, the two halves do not match. |
| B | Border | Ragged, notched, blurred or irregular edges rather than smooth, well-defined margins. |
| C | Colour | Multiple shades within a single lesion: tan, brown, black, red, white or blue. |
| D | Diameter | Larger than 6 mm (approximately the diameter of a pencil eraser) — though early melanomas can be smaller. |
| E | Evolution | Any change over weeks to months in size, shape, colour, elevation or symptoms (bleeding, itching, crusting). This is the most important criterion. |
A practical addition is the "ugly duckling" sign: any mole that looks distinctly different from the patient's other moles (whether larger, smaller, darker, or more isolated) deserves attention, even if it does not strictly meet ABCDE criteria.
Additional Warning Signs Beyond Pigmented Lesions
Not all skin cancers appear as dark moles. Be alert to:
- A sore that does not heal within 4–6 weeks.
- A new growth that bleeds spontaneously or with minor trauma.
- A pearly, shiny bump on sun-exposed skin (classic BCC appearance).
- A flat, scaly red patch that persists and does not respond to emollients (may be SCC in situ / Bowen's disease).
- A dark streak under a fingernail or toenail not caused by trauma (subungual melanoma).
- Any lesion with associated satellite lesions (small similar spots near the main lesion).
Risk Factors for Skin Cancer
High-Risk Factors
- Personal history of skin cancer: A prior diagnosis significantly increases risk of a second primary tumour.
- Family history of melanoma: First-degree relatives with melanoma increase risk 2–3-fold; familial melanoma syndromes (e.g., CDKN2A mutations) carry much higher lifetime risk.
- Large number of nevi (>50) or atypical (dysplastic) nevi: Atypical moles share histological features with early melanoma and serve as a marker of elevated risk.
- Immunosuppression: Organ transplant recipients on immunosuppressive therapy have a 65–250-fold increased risk of SCC.
- Fitzpatrick skin type I–II: Very fair skin, freckling, light eyes and hair with poor tanning response.
Modifiable Risk Factors
- Cumulative UV exposure (both recreational and occupational).
- History of sunburns, especially blistering sunburns in childhood.
- Tanning bed use — each session increases melanoma risk; use before age 35 increases risk by 59%.
- Tobacco smoking (increases SCC risk, particularly lip cancer).
Skin Cancer Screening: What It Involves
Self-Examination
Monthly full-body self-examination in good lighting, using a full-length mirror and a hand mirror for hard-to-see areas, is the foundation of early detection. Systematically examine: face, scalp (using a comb or hair dryer to part hair), neck, chest, abdomen, arms (including axillae), back, buttocks, legs and feet (including soles and between toes), and under fingernails and toenails. Use a phone camera to photograph moles that are difficult to see; comparing photographs month to month helps identify subtle changes.
Professional Skin Check (Total Body Dermoscopy)
A professional skin examination by a trained dermatologist or aesthetic physician using dermoscopy (dermatoscopy) is the gold standard for mole evaluation. Dermoscopy uses magnification and cross-polarised light to visualise sub-surface structures invisible to the naked eye, significantly improving the sensitivity and specificity of melanoma detection compared to unaided visual examination.
Who should have regular professional skin checks:
- All adults annually from age 30 (earlier for high-risk individuals).
- Anyone with more than 50 moles.
- Anyone with personal or family history of skin cancer.
- Individuals with atypical or changing lesions.
- Immunocompromised patients — every 3–6 months.
- Anyone who has used tanning beds.
Total Body Photography (TBP)
For high-risk patients (multiple atypical nevi, personal history of melanoma), baseline total body photography followed by sequential dermoscopic monitoring of individual lesions enables detection of very early change that would otherwise be missed. Dedicated dermoscopy software with AI-assisted analysis is increasingly available in specialist centres.
Biopsy and Histopathology
When a lesion is clinically or dermoscopically suspicious, excision or punch biopsy followed by histopathological examination is the definitive diagnostic step. No visual or AI-based tool replaces histopathology for diagnostic certainty.
What Happens After a Suspicious Lesion Is Found
If a suspicious lesion is identified — either by self-examination or during a professional skin check — the following pathway applies:
- Dermoscopic evaluation: To stratify the lesion's risk and decide between monitoring and excision.
- Excision biopsy: Removal of the lesion with a margin of normal tissue; sent for histopathological analysis.
- Histopathology report: Confirms diagnosis, tumour type, Breslow thickness (for melanoma), and margin status.
- Staging and further management: Depends on tumour type and stage. BCC and SCC in situ are typically cured by excision. Invasive SCC may require wider excision and lymph node assessment. Melanoma staging determines whether sentinel lymph node biopsy, imaging, or systemic therapy is required.
Early-stage BCC and SCC can also be treated with Mohs micrographic surgery, topical immunotherapy (imiquimod), photodynamic therapy (PDT), or cryotherapy in selected cases — the choice depends on tumour subtype, location and patient factors.
Prevention Strategies
- Daily broad-spectrum SPF 50+ sunscreen on all sun-exposed areas — the most evidence-based intervention for reducing skin cancer risk.
- Seek shade between 10 am and 4 pm when the UV index is highest.
- Physical sun protection: Wide-brimmed hats, UPF 50+ clothing, sunglasses with UV400 lenses.
- Never use tanning beds — there is no safe dose of artificial UV for the purpose of tanning.
- Vitamin D via supplementation rather than deliberate UV exposure (1000–2000 IU D3 daily is safe and adequate for most adults).
- Annual professional skin checks from age 30, or earlier for high-risk individuals.
Frequently Asked Questions
What is the ABCDE rule for skin cancer?
The ABCDE rule is a self-examination guide: A = Asymmetry, B = Border irregularity, C = Colour variation, D = Diameter greater than 6 mm, E = Evolution (any change over time). A lesion that meets one or more of these criteria should be evaluated by a dermatologist.
How often should skin cancer screening be done?
Adults with average risk should perform monthly self-examinations and have a professional full-body skin check annually. Those with high-risk factors (personal or family history of melanoma, numerous atypical nevi, immunosuppression) may require checks every 3–6 months.
Can skin cancer appear on areas not exposed to the sun?
Yes. While UV-exposed areas are most commonly affected, melanoma in particular can arise in non-sun-exposed sites including the soles of the feet, palms, under fingernails and toenails (acral lentiginous melanoma), and on mucosal surfaces.
Is a changing mole always skin cancer?
Not necessarily, but any change in a mole — in size, shape, colour or surface — warrants prompt professional evaluation. Most changing moles are benign, but only dermoscopic examination by a qualified dermatologist can reliably distinguish benign from malignant lesions.
References
- Geller AC, Swetter SM, Brooks K, Demierre MF, Yaroch AL. "Screening, early detection, and trends for melanoma: current status (2000–2006) and future directions." J Am Acad Dermatol. 2007;57(4):555–572. [PubMed]
- Siegel RL, Miller KD, Jemal A. "Cancer statistics, 2022." CA Cancer J Clin. 2022;72(1):7–33.
- World Health Organization — Skin cancer prevention. [WHO]
- American Academy of Dermatology — Melanoma warning signs. [AAD]
- Argenziano G, Soyer HP, Chimenti S, et al. "Dermoscopy of pigmented skin lesions: results of a consensus meeting via the Internet." J Am Acad Dermatol. 2003;48(5):679–693.
This article is for informational purposes only. Please consult a qualified physician for treatment decisions.