Subungual Melanoma: Diagnosis, Nail Biopsy, and Surgical Wide Excision

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

Subungual melanoma — malignant melanoma arising from the nail matrix or nail bed beneath the toenail or fingernail — accounts for 0.7–3.5% of all melanomas in Caucasians and a disproportionately higher percentage in darker-skinned populations, and is the most commonly misdiagnosed malignancy of the foot due to its resemblance to subungual hematoma, fungal nail infection, and nail dystrophy. Biopsy delay beyond 6–12 months from first clinical suspicion is associated with increased tumor thickness (Breslow depth) and worse prognosis — making early recognition and prompt nail biopsy the critical intervention that saves lives.

Clinical Recognition: Differentiating from Benign Conditions

Subungual melanoma features: longitudinal melanonychia (brown-black longitudinal stripe along the nail) — the key presenting sign; the ‘ABCDEF criteria for nail melanoma’: A = Age (40–70 peak) and African/Asian/Native American ancestry (higher incidence); B = Band width >3mm, lack of Borders (irregular); C = Change in band width or color over time; D = Digit involvement (hallux, thumb, or index finger most common); E = Extension of pigment to the perionychial skin (Hutchinson’s sign — pathognomonic for melanoma); F = Family or personal history of melanoma. Pitfalls: the ‘Pseudo-Hutchinson’s sign’ — periungual pigmentation can occur with subungual hematoma (distinguish by history of trauma and proximal migration of the discoloration). Subungual hematoma: pain at onset, proximal nail growth with clear nail appearing proximally over weeks; subungual melanoma does not migrate proximally. Annual prevalence: subungual melanoma is rare — 25–35 new cases per million per year; but the consequences of missed diagnosis are devastating — 5-year survival with early detection (Stage I) is 80–95% vs. 15–30% with metastatic disease.

Diagnosis and Surgical Management

Nail matrix biopsy (the diagnostic gold standard): longitudinal biopsy technique under digital nerve block; nail plate removed; biopsy through the nail bed/matrix including the full thickness to the periosteum; 3–4mm punch or tangential shave biopsy depending on lesion characteristics; histopathology confirms melanoma diagnosis and establishes Breslow depth. Surgical wide local excision: distal toe or finger amputations are NO LONGER the standard — wide local excision with 1cm margins (for Breslow <1mm) or 2cm margins (>1mm) with sentinel lymph node biopsy is the current evidence-based approach; the digit is preserved when oncologic margins can be achieved. Sentinel lymph node biopsy: performed for Breslow depth >0.8mm; inguinal SLN for hallux melanoma; SLN positivity rate 20–30% for subungual melanoma; positive SLN guides adjuvant immunotherapy. Adjuvant therapy: anti-PD-1 immunotherapy (pembrolizumab, nivolumab) for Stage III–IV disease; targeted therapy (BRAF inhibitors) for BRAF-mutated melanoma. Dr. Biernacki at Balance Foot & Ankle evaluates suspicious nail lesions and performs nail matrix biopsy for subungual melanoma diagnosis at our Bloomfield Hills and Howell offices. Call (810) 206-1402.

📧 Get Dr. Tom’s Free Lab Test Guide

Discover the 5 lab tests every person over 35 should ask their doctor about — explained in plain English by a board-certified physician.

Download Your Free Guide →

📍 Located in Michigan?

Our board-certified podiatrists treat this condition at two convenient locations. Same-day appointments often available.

Book Now →
(810) 206-1402

Frequently Asked Questions

What is the most effective treatment for toenail fungus?

Oral antifungal medications (terbinafine, itraconazole) have the highest cure rates at 70–80%. Prescription topical treatments (efinaconazole, tavaborole) are safer but slower. Laser treatment is a pain-free option. Complete clearance takes 9–18 months as new nail grows in.

How long does it take to cure toenail fungus?

Fungal nail infections are slow to clear because nails grow slowly. With treatment, you may see initial improvement in 3–4 months, but complete clearance of a toenail takes 9–12 months (toenails grow about 1.5mm per month).

Can toenail fungus spread to other nails or family members?

Yes, fungal infections can spread to adjacent toenails and less commonly to skin (athlete’s foot) or family members through shared surfaces. Using flip-flops in showers, not sharing nail clippers, and treating promptly reduces spread risk.

Need Treatment at Balance Foot & Ankle?

Dr. Tom Biernacki, Dr. Carl Jay, and Dr. Daria Gutkin see patients at our Howell and Bloomfield Township offices.

Book Online or call (810) 206-1402

Foot & Nail Melanoma Diagnosis in Michigan

Balance Foot & Ankle provides expert evaluation of suspicious nail and foot lesions. Early detection of subungual melanoma is critical — our podiatrists perform biopsy and coordinate with oncology for treatment.

Learn About Our Toenail & Skin Evaluations → | Book Your Appointment | Call (810) 206-1402

Clinical References

1. Levit EK, et al. The ABC rule for clinical detection of subungual melanoma. J Am Acad Dermatol. 2000;42(2 Pt 1):269-274.
2. Bristow IR, et al. Clinical guidelines for the recognition of melanoma of the foot and nail unit. J Foot Ankle Res. 2010;3:25.
3. Phan A, et al. Acral lentiginous melanoma: a clinicoprognostic study of 126 cases. Br J Dermatol. 2006;155(3):561-569.

Most Common Mistake We See

The most common mistake we see is: Waiting too long before seeking care. Fix: any foot pain lasting more than 4 weeks, or any sudden severe symptom, deserves a professional evaluation rather than more rest.

Warning Signs That Need Same-Day Care

What is Foot pain?

Foot pain is a common foot/ankle condition that affects mobility and quality of life. Understanding the underlying cause is the first step in successful treatment. Our podiatrists at Balance Foot & Ankle perform a hands-on biomechanical exam, review your activity history, and use diagnostic imaging when appropriate to identify the root cause—not just treat the symptom. Many patients have been told to “rest and ice” without a deeper diagnostic workup; our approach is different.

Symptoms and warning signs

Common signs of foot pain include pain that worsens with activity, morning stiffness, swelling, tenderness when palpated, and difficulty bearing weight. If you experience sudden severe pain, inability to walk, visible deformity, numbness or color change, contact our office the same day or visit urgent care—these can signal a more serious injury such as a fracture, tendon rupture, or vascular compromise. Diabetics with any foot wound should seek same-day care.

Conservative treatment options

Most cases of foot pain respond to non-surgical care: structured rest, supportive footwear changes, custom orthotics, targeted stretching and strengthening protocols, anti-inflammatory medications when medically appropriate, and in-office procedures such as ultrasound-guided injections. We also offer advanced therapies including MLS laser therapy, EPAT/shockwave, regenerative injections, and image-guided procedures. Treatment is sequenced from least invasive to most invasive, and we explain the rationale at every step.

When is surgery considered?

Surgery is reserved for cases that fail 3-6 months of well-structured conservative care, when there is structural pathology (severe deformity, complete tear, advanced arthritis), or when imaging shows damage that will not heal without intervention. Our surgeons have performed 3,000+ foot and ankle procedures and prioritize minimally-invasive techniques whenever appropriate. We discuss recovery timelines, return-to-activity milestones, and realistic outcome expectations before any procedure is scheduled.

Recovery timeline and prevention

Recovery from foot pain varies based on severity and chosen treatment path. Conservative cases often improve within 4-8 weeks with consistent adherence to the protocol. Post-procedural recovery may range from a few days (in-office procedures) to several months (reconstructive surgery). Long-term prevention involves footwear assessment, activity modification, structured strengthening, and regular check-ins with your podiatrist if you have a history of recurrence. We provide written home-exercise plans and digital follow-up support.