How should I manage a 78-year-old woman with prior skin cancer who has a pea-sized erythematous lesion with raised borders and a dry, cracked central area on her left middle finger?

Management of Suspicious Finger Lesion in Elderly Patient with Skin Cancer History

This lesion requires immediate biopsy to rule out squamous cell carcinoma (SCC) or basal cell carcinoma (BCC), as the clinical presentation—raised erythematous borders with central cracking on a sun-exposed digit in a patient with prior skin cancer—is highly suspicious for malignancy. 1, 2

Immediate Diagnostic Approach

Perform a biopsy before any definitive treatment. The finger location represents a high-risk anatomic site, and the clinical description suggests possible keratinocyte carcinoma. 1

• Biopsy technique: Use a punch or shave biopsy that includes deep reticular dermis, as superficial biopsies may miss infiltrative components present at deeper margins 1, 3
• Provide pathologist with key information: Patient age (78), anatomic location (finger), lesion size (pea-sized, approximately 1 cm), and history of prior skin cancer 2
• Histopathological assessment must evaluate: Degree of cellular differentiation, presence of aggressive histologic subtypes, depth of invasion, and perineural or lymphovascular invasion 2

Risk Stratification

The finger location is inherently high-risk for several reasons:

• Anatomic considerations: Digits are considered high-risk locations for both SCC and BCC due to increased recurrence rates and potential for functional impairment 1
• Size threshold: Even small lesions (<2 cm) on high-risk locations like fingers warrant aggressive management 1
• Patient factors: Age 78 with prior skin cancer history increases likelihood of additional malignancies 1

Definitive Management Based on Biopsy Results

If Confirmed Malignancy (SCC or BCC):

Surgical excision is the treatment of choice for cutaneous malignancies on the hand. 1, 2

• For well-defined, low-risk tumors <2 cm: Surgical excision with minimum 4-mm margins achieves 95% complete removal 1
• For high-risk features (finger location qualifies): Use 6-mm or wider margins with histological examination of tissue margins, or consider Mohs micrographic surgery 1
• Mohs surgery advantages: Particularly valuable on digits where tissue preservation is critical for function while ensuring complete tumor removal 1

Surgical Planning Considerations:

• Functional preservation: The finger location demands careful surgical planning to maintain hand function while achieving oncologic clearance 2, 4
• Reconstruction: Plan for potential skin grafting or local flaps if wide excision creates significant defect 4
• Multidisciplinary discussion: Cases involving digits should be discussed with dermatologists, plastic surgeons, and histopathologists to optimize both oncologic and functional outcomes 2

If Actinic Keratosis (Less Likely Given Description):

If biopsy reveals only actinic keratosis rather than invasive carcinoma:

• Topical 5-fluorouracil: Apply twice daily for 2-4 weeks until inflammatory response reaches erosion stage 5
• Imiquimod cream: Not ideal for finger lesions due to application challenges, but could be considered for field treatment 6
• Cryotherapy: Acceptable for isolated lesions but requires careful application on digits 1

Critical Pitfalls to Avoid

• Never delay biopsy: Clinical diagnosis alone is insufficient, especially with prior skin cancer history 1, 2, 7
• Avoid inadequate margins: Fingers have limited tissue, but insufficient margins dramatically increase recurrence risk 1, 2
• Don't use topical therapy without histologic confirmation: The clinical description suggests possible invasive disease, which requires surgical management 1
• Assess regional lymph nodes: Palpate epitrochlear and axillary nodes; if suspicious, perform ultrasound-guided fine-needle aspiration 2

Follow-Up Protocol

After definitive treatment:

• Initial surveillance: Every 3-6 months for the first year, then annually 2
• Complete skin examination: Patients with one skin cancer have increased risk for additional malignancies including melanoma 1
• Patient education: Instruct on self-monitoring for new lesions, persistent ulceration, or suspicious changes requiring immediate re-evaluation 2
• Sun protection counseling: Essential for preventing additional lesions 1

The key message: Do not attempt empiric treatment without tissue diagnosis. The combination of raised borders, central changes, finger location, and prior skin cancer history mandates histologic confirmation before proceeding with definitive therapy. 1, 2, 7