Squamous Cell Carcinoma
Also known as: SCC, SCC Skin Cancer, Squamous Cell Skin Cancer
Second most common skin cancer. More aggressive than BCC - can spread to lymph nodes if not treated early.
What to look for
Side-by-side comparison
Normal skin
No rough patches
Possible SCC
Firm red nodule, scaly crust
Squamous cell carcinoma (SCC) of the skin develops in the flat squamous cells that form the outer layer of the epidermis. It is the second most common skin cancer after BCC, with over one million cases diagnosed annually in the US.
Unlike BCC, SCC carries a real risk of metastasis. Approximately 2-5% of cutaneous SCCs spread to regional lymph nodes or distant sites, and this risk rises sharply for tumors that are large (>2cm), deep (>2mm thick), poorly differentiated, located on the ear or lip, occur in immunosuppressed patients, or arise in chronic wounds or scars.
SCC typically presents as a firm, red nodule or a flat lesion with a rough, scaly, or crusted surface. It most commonly appears on chronically sun-exposed areas: the face, ears, neck, scalp (in bald individuals), back of hands, and forearms. Unlike BCC's pearly translucence, SCC tends to look more opaque and flesh-colored to red.
Many SCCs develop from pre-existing actinic keratoses (AKs). This progression from AK to SCC is why dermatologists recommend treating all actinic keratoses rather than simply monitoring them.
SCC can also develop in areas of chronic inflammation, scarring (Marjolin ulcer), radiation-damaged skin, or in association with human papillomavirus (HPV) - particularly on the genitals and around the nails.
Quick self-check
Does this look like squamous cell carcinoma? Answer 2 questions.
Is the spot firm, raised, or nodular with a rough or scaly surface?
Is it on a chronically sun-exposed area (face, ears, hands, scalp)?
Risk factors
- Cumulative lifetime sun exposure (more important than acute burns for SCC)
- Fair skin (Fitzpatrick types I-III)
- History of actinic keratosis - the primary precursor lesion
- Weakened immune system (transplant recipients have 65-250x increased risk)
- Previous SCC or other skin cancer
- Human papillomavirus (HPV) infection
- Chronic wounds, scars, or sites of chronic inflammation
- Exposure to arsenic or certain industrial chemicals
- Previous radiation therapy to the area
When to see a dermatologist
- ⚠A firm, red nodule on sun-exposed skin that persists or grows
- ⚠A flat sore with a rough, scaly, or crusted surface
- ⚠A new raised or thickened area on an old scar or chronic wound
- ⚠A rough, scaly patch on the lip that does not heal
- ⚠Any rapidly growing skin lump, especially in immunosuppressed individuals
Often confused with
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Full ABCDE check →Frequently asked questions
How is SCC different from BCC?
SCC grows faster, looks more opaque and scaly (versus BCC's pearly translucence), and has a meaningful risk of spreading to lymph nodes (2-5% overall, much higher in certain subtypes). BCC almost never metastasizes. Both need treatment, but SCC requires more aggressive follow-up.
Can SCC develop from actinic keratosis?
Yes. AK is considered the direct precursor to SCC. An estimated 5-10% of untreated actinic keratoses progress to SCC over time. Since it is impossible to predict which ones will transform, dermatologists recommend treating all AKs.
Who is at highest risk for aggressive SCC?
Organ transplant recipients face dramatically increased risk (65-250 times higher than the general population) and tend to develop more aggressive tumors. Immunosuppressed patients, those with SCC on the ear or lip, and tumors larger than 2cm or deeper than 2mm also carry higher metastatic risk.
Related conditions
Actinic Keratosis
Rough, sandpaper-like patches from years of sun damage. The most common precancer - 5-10% progress to squamous cell carcinoma.
Bowen's Disease
Early-stage SCC confined to the top skin layer. A persistent, well-defined red scaly patch - 3-5% progress to invasive cancer.
Basal Cell Carcinoma
The most common cancer in humans. Slow-growing, rarely spreads, but can cause serious tissue damage if untreated.
Cutaneous Horn
Hard cone-shaped keratin projection. The horn is harmless - but 16% hide cancer at the base.