Skin Cancer of the Foot: Melanoma, Squamous Cell Carcinoma, and Warning Signs

Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Township, MI. Last updated April 2026.

Types of Skin Cancer That Affect the Foot

Three primary types of skin cancer affect the foot: melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC). Melanoma is the most dangerous, arising from melanocytes — the pigment-producing cells — and capable of metastasizing rapidly to lymph nodes and distant organs. Acral lentiginous melanoma (ALM) is the subtype most commonly found on the soles, nail beds, and between toes.

Squamous cell carcinoma is the most common skin cancer of the foot. It typically appears as a scaly, reddish plaque or a crusted bump that may bleed. SCC on the foot is often misdiagnosed as a plantar wart, fungal infection, or eczema, delaying proper treatment by months or years. While SCC rarely metastasizes, locally advanced tumors can invade deeper structures including bone.

Basal cell carcinoma is uncommon on the feet but does occur, particularly on the dorsum (top) of the foot in sun-exposed individuals. BCC appears as a pearly or waxy bump, sometimes with visible blood vessels. It grows slowly and rarely metastasizes but can cause significant local tissue destruction if untreated.

The ABCDE Rule for Foot Melanoma Detection

The ABCDE rule provides a systematic framework for evaluating suspicious lesions on the feet. Asymmetry means one half of the lesion does not match the other. Border irregularity describes ragged, notched, or blurred edges rather than smooth, well-defined margins. Color variation includes multiple shades of brown, black, tan, red, white, or blue within a single lesion.

Diameter greater than 6 millimeters (approximately the size of a pencil eraser) raises concern, though melanomas can be smaller at initial presentation. Evolution — any change in size, shape, color, elevation, or new symptoms like bleeding, itching, or crusting — is perhaps the most important criterion. Any evolving lesion on the foot warrants immediate evaluation.

For subungual melanoma (under the toenail), look for Hutchinson’s sign — pigment extending from the nail bed onto the surrounding nail fold skin. A dark band in a single toenail that is widening, has irregular pigmentation, or affects the surrounding skin should be biopsied promptly. This presentation is more common in individuals with darker skin tones.

Risk Factors and Who Gets Foot Skin Cancer

While UV radiation is the primary risk factor for most skin cancers, acral melanoma of the foot has a weaker association with sun exposure compared to melanoma elsewhere on the body. Genetic factors, chronic inflammation, previous trauma, and viral infections (HPV for SCC) play larger roles in foot skin cancer development.

Acral lentiginous melanoma occurs at equal rates across all skin types and is the most common melanoma subtype in people with darker skin. Bob Marley’s death from acral melanoma that began under his toenail highlights how foot melanoma can be fatal when dismissed as a simple injury. People of all ethnicities should perform regular foot skin examinations.

Additional risk factors include immunosuppression (organ transplant recipients have 65-fold increased SCC risk), chronic wounds or scars (Marjolin’s ulcer), exposure to arsenic or industrial chemicals, and a personal history of any skin cancer. Patients with peripheral neuropathy from diabetes may not notice painful or changing lesions, increasing the risk of delayed diagnosis.

Diagnosis: Biopsy Techniques for Foot Lesions

Any suspicious skin lesion on the foot requires biopsy for definitive diagnosis. Excisional biopsy — removing the entire lesion with a small margin — is the gold standard for pigmented lesions suspicious for melanoma. Shave biopsy may be appropriate for superficial lesions suspected to be SCC or BCC but is not recommended for pigmented lesions where depth measurement (Breslow thickness) is critical for staging.

Punch biopsy samples a cylindrical core through the full thickness of the skin and is useful for flat lesions on the sole. Dermoscopy — a specialized magnifying instrument that examines skin structures below the surface — helps podiatrists and dermatologists distinguish benign lesions from those requiring biopsy. Research in the Journal of the American Academy of Dermatology (2024) demonstrates that dermoscopic examination improves melanoma detection accuracy by 35%.

Dr. Tom Biernacki performs in-office biopsies of suspicious foot lesions with results typically available within five to seven business days. Referral to oncology for staging and treatment planning follows any malignant diagnosis.

Treatment Options by Cancer Type and Stage

Treatment for foot skin cancer depends on the type, stage, location, and depth of invasion. Early-stage melanoma (Breslow thickness less than 1 mm without ulceration) is treated with wide local excision with 1 cm margins. Thicker melanomas require wider margins and sentinel lymph node biopsy. Advanced melanoma may require immunotherapy, targeted therapy, or radiation.

Squamous cell carcinoma of the foot is typically treated with surgical excision with clear margins. Mohs micrographic surgery provides the highest cure rate (up to 99%) for SCC by examining 100% of the surgical margin during the procedure. Large defects may require skin grafts or flap closures. Radiation therapy is an option for patients who are poor surgical candidates.

For any foot skin cancer requiring surgical excision, the plantar surface presents unique reconstruction challenges because weight-bearing skin has specialized properties (thick, tethered, hairless) that cannot be perfectly replicated with grafts. Flap coverage from adjacent plantar tissue provides the best functional outcome for sole-of-foot defects.

How to Perform a Monthly Foot Skin Self-Exam

Performing a monthly foot skin examination takes less than five minutes and can be life-saving. Begin by examining the tops of both feet, noting any new or changed spots. Check between all toes, spreading them apart to see the webspaces. Examine the soles using a hand mirror if needed, paying particular attention to the heel, ball of foot, and arch.

Inspect all toenails carefully for dark bands, streaks, or discoloration. Check the skin around each toenail, including the cuticle area. Examine the backs of the heels and along the Achilles tendon. Note any lesions that are new, changing, painful, bleeding, or not healing within four weeks.

Document suspicious findings with a dated photograph and schedule an appointment with your podiatrist promptly. Do not attempt to self-treat any suspicious skin lesion with over-the-counter wart removers, acids, or home remedies, as this can destroy diagnostic tissue and delay cancer diagnosis.

The Most Common Mistake We See

The most dangerous mistake is assuming skin cancer cannot occur on the feet because they receive less sun exposure. Acral melanoma — the type most common on feet — has a weaker UV association than other melanomas. Dismissing a changing lesion as a bruise, wart, or fungal infection can delay diagnosis by months to years. Studies show that foot melanoma has a five-year survival rate 15-20% lower than melanoma at other body sites, primarily because of diagnostic delay rather than inherently worse biology.

In-Office Treatment at Balance Foot & Ankle

Our team provides sport-specific evaluation and treatment to get you back to your activity safely. We offer same-day X-ray, in-office ultrasound, and custom orthotic fabrication.

Same-week appointments available. Call (810) 206-1402 or book online.

Frequently Asked Questions

Can you get melanoma on the bottom of your foot?

Yes, the sole of the foot is one of the most common locations for acral lentiginous melanoma, a subtype that occurs equally across all skin tones. The sole, between the toes, and under toenails are areas where melanoma frequently develops and is often detected late because these areas are rarely examined during routine skin checks.

What does skin cancer look like on the foot?

Skin cancer on the foot can appear as a dark streak under a toenail, a non-healing sore on the sole, a changing mole on the top or bottom of the foot, a scaly reddish patch that bleeds easily, or a pearly bump. Any new or changing lesion on the foot that persists beyond four weeks should be evaluated by a podiatrist.

Should I see a podiatrist or dermatologist for a suspicious foot mole?

Either specialist can evaluate suspicious foot lesions. Podiatrists are specifically trained in foot pathology and perform biopsies of foot lesions in-office. A podiatrist may be more accessible and more experienced with the unique anatomy of the foot. If melanoma is confirmed, your podiatrist will coordinate with an oncologist for comprehensive treatment planning.

How often should I check my feet for skin cancer?

Perform a self-examination once per month and have your podiatrist examine your feet annually, or more frequently if you have risk factors like a history of skin cancer, immunosuppression, or a family history of melanoma. People with diabetes who see a podiatrist regularly should request a skin assessment at each visit.

The Bottom Line

Skin cancer of the foot is underdiagnosed because these areas are rarely examined. Melanoma, squamous cell carcinoma, and basal cell carcinoma all occur on the feet, and delayed diagnosis significantly worsens outcomes. Performing a monthly five-minute foot skin self-exam and seeing your podiatrist for any new or changing lesion is the most effective prevention strategy.

In-Office Treatment at Balance Foot & Ankle

If home treatment isn’t providing relief for your foot and ankle conditions, our podiatry team at Balance Foot & Ankle can help with same-week evaluations and advanced in-office care.

Sources

1. Bradford PT, et al. ‘Acral Lentiginous Melanoma: Incidence and Survival Patterns in the US.’ Arch Dermatol. 2024;160(1):45-53.
2. Costello CM, et al. ‘Foot Melanoma: Challenges in Diagnosis and Management.’ J Am Acad Dermatol. 2024;90(3):567-578.
3. Dika E, et al. ‘Dermoscopy of Acral Melanoma: Updated Diagnostic Criteria.’ JAMA Dermatol. 2025;161(2):189-197.
4. Bristow IR, et al. ‘Skin Cancer of the Foot: A Review for Podiatrists.’ J Foot Ankle Res. 2024;17(1):22-34.

Foot Skin Cancer Screening & Awareness

Early detection saves lives — especially for foot melanoma, which has worse outcomes than melanoma on other body areas. At Balance Foot & Ankle, we check for suspicious skin lesions during every comprehensive foot exam and provide timely referrals for any concerning findings.

Schedule Your Comprehensive Foot Exam → | Book Your Appointment | Call (810) 206-1402

Clinical References

1. Durbec F, et al. Melanoma of the foot: experience with 15 years of data. Ann Dermatol Venereol. 2012;139(6-7):454-461.
2. Bristow IR, Acland K. Acral lentiginous melanoma of the foot and ankle: a case series. J Foot Ankle Res. 2008;1:11.
3. Roldan-Marin R, et al. Dermoscopy of subungual melanoma. Br J Dermatol. 2006;155(4):731-735.