What is the appropriate diagnosis and treatment approach for an elderly patient presenting with a skin lesion, considering the possibility of skin cancer, such as basal cell carcinoma, squamous cell carcinoma, or melanoma?

Elderly Skin Lesions: Diagnosis and Treatment Approach

For elderly patients presenting with skin lesions, clinicians should remain alert for malignant features during routine examinations and perform excisional biopsy of any suspicious lesion, followed by treatment based on histopathologic diagnosis, though routine screening of asymptomatic patients lacks evidence for mortality benefit. 1

Clinical Assessment of Suspicious Lesions

Evaluate all skin lesions using the ABCDE criteria to identify features warranting biopsy: 1

• Asymmetry of the lesion 1
• Border irregularity 1
• Color heterogeneity or variability 1
• Diameter >6 mm (though many melanomas now present <5 mm) 1
• Evolution or dynamics - any change in size, color, or elevation over time is particularly important 1

Dermoscopy by an experienced physician significantly enhances diagnostic accuracy and should be used when available. 1

Risk Factors Requiring Heightened Vigilance

Elderly patients with the following characteristics warrant particularly careful examination: 1

• Fair skin complexion 1
• Male sex (higher melanoma mortality in elderly males) 1
• History of extensive sun exposure or sunburns 1
• Multiple (≥100) nevi or atypical/dysplastic nevi 1
• Personal or family history of skin cancer 1

Diagnostic Approach

Perform full-thickness excisional biopsy with a 2-5 mm margin of normal skin and subcutaneous fat for any suspicious pigmented or changing lesion. 1, 2, 3

Critical Biopsy Principles

• Excisional biopsy is mandatory - shave and punch biopsies are contraindicated as they prevent accurate Breslow thickness measurement and staging 2
• Include the entire lesion when possible to avoid sampling error 2
• Incisional biopsy is only acceptable for large facial lesions (lentigo maligna) or when complete excision is impractical 1, 2
• Use a surgical knife rather than laser or electrocautery to preserve tissue architecture 3

Essential Pathology Documentation

The pathology requisition must include: 1, 4

• Precise anatomic location with laterality (e.g., "left dorsal forearm") 4
• Patient age and sex 4
• Clinical diameter of the lesion 4
• Whether the lesion is primary, recurrent, or at a previously irradiated site 4
• Immunosuppression status if applicable 4

The histopathology report must document: 1, 3

• Breslow thickness to the nearest 0.1 mm (measured from granular layer to tumor base) 1
• Presence or absence of ulceration 1
• Surgical margin clearance 1
• Mitotic rate (prognostic value) 1
• Clark level of invasion 1, 3

Treatment Based on Diagnosis

Melanoma

Wide local excision margins depend on Breslow thickness: 2, 3

• <1 mm depth: 1 cm margin 2
• 1-2 mm depth: 1-2 cm margin (minimum 1 cm where functionally appropriate) 1, 2
• >2 mm depth: 2 cm margin 2

Sentinel lymph node biopsy should be discussed for: 2

• Lesions ≥0.8-1.0 mm thickness 2
• Thinner lesions with adverse features (ulceration, high mitotic rate) 2

Treatment involves excision with or without lymph node management depending on stage. 1

Basal Cell Carcinoma (BCC)

Multiple treatment options exist with excellent cure rates: 1

• Surgical excision 1
• Mohs micrographic surgery (preferred for high-risk locations) 1
• Curettage and electrodesiccation 1
• Cryosurgery 1
• Radiation therapy 1

For superficial BCC when conventional methods are impractical (multiple lesions, difficult sites), topical 5-fluorouracil 5% cream applied twice daily for 3-6 weeks (up to 10-12 weeks) achieves approximately 93% success rate. 5

Squamous Cell Carcinoma (SCC)

Treatment options mirror BCC and include: 1

• Surgical excision 1
• Mohs micrographic surgery 1
• Radiation therapy 1
• Curettage and electrodesiccation 1

Actinic Keratosis (Premalignant)

Topical 5-fluorouracil cream applied twice daily for 2-4 weeks until inflammatory response reaches erosion stage, with complete healing occurring 1-2 months after cessation. 5

Important Caveats

Screening asymptomatic elderly patients has uncertain benefit-to-harm ratio: 1

• The USPSTF gives an "I" (insufficient evidence) grade for routine whole-body skin examination screening 1
• Between 20-55 excisions are performed to detect 1 melanoma, with over 4,000 excisions estimated to prevent 1 melanoma death 1
• Overdiagnosis and overtreatment are significant concerns 1

However, clinicians should remain vigilant during examinations performed for other purposes and biopsy any lesion with malignant features. 1

Clinical diagnosis accuracy is limited: 1, 6

• Primary care physicians have 42-100% sensitivity for melanoma diagnosis 1
• Positive predictive value for clinical melanoma diagnosis is only 33.3% 6
• 20.9% of melanomas were initially misclassified as common nevi 6

This underscores the critical importance of low threshold for biopsy of any changing or suspicious lesion in elderly patients, as the consequences of missing a melanoma far outweigh the minor morbidity of an excisional biopsy.