What are the evaluation and treatment options for a suspicious skin lesion based on its characteristics?

Evaluation and Management of Suspicious Skin Lesions

Any suspicious skin lesion should undergo complete excisional biopsy with 2-5 mm margins of normal skin and a cuff of subcutaneous fat, never shave or punch biopsy, as these compromise pathological staging and may miss deeper infiltrative components. 1

Initial Clinical Assessment

Complete skin examination is mandatory for all patients presenting with a suspicious lesion, as this identifies additional concurrent malignancies in a substantial proportion of patients 1. The examination should include:

• Full body skin surface inspection including scalp, to detect second primary melanomas or concurrent skin cancers 1
• Regional lymph node palpation for lymphadenopathy 1
• Abdominal examination for hepatomegaly in melanoma suspects 1
• Documentation of lesion site, size, and characteristics with clinical photography when feasible 1

ABCDE Criteria for Melanoma Suspicion

The American Joint Committee on Cancer recommends the ABCDE schema for evaluating pigmented lesions 2:

• A (Asymmetry): One half differs from the other 1, 2
• B (Border irregularity): Irregular, scalloped, or poorly defined edges 1, 2
• C (Color heterogeneity): Variegated pigmentation with multiple colors 1, 2
• D (Diameter): Greater than 6 mm, though many early melanomas are smaller 1, 2
• E (Evolution): Recent change in size, color, or shape—this must coexist with at least one other criterion 1, 2

Dermoscopy by an experienced examiner significantly improves diagnostic accuracy over visual inspection alone, with a relative diagnostic odds ratio of 4.7 for in-person evaluations and 5.6 for image-based evaluations 3. At 80% specificity, dermoscopy increases sensitivity by 16% for in-person diagnosis and 34% for image-based diagnosis compared to visual inspection alone 3.

Risk Stratification for Basal Cell Carcinoma

Location and size are critical risk factors for BCC recurrence 1:

• High-risk locations: "H-zone" or mask areas of the face, head and neck region 1
• High-risk size thresholds: ≥6 mm in high-risk facial locations, ≥10 mm in moderate-risk locations 1
• Additional high-risk features: Deep soft tissue involvement, bone involvement, perineural invasion 1

Imaging with MRI is preferred over CT when perineural disease or deep soft tissue involvement is suspected due to higher sensitivity 1.

Biopsy Technique Requirements

For Suspected Melanoma

Full-thickness excisional biopsy is the only acceptable approach in primary care 1:

• Include 2-5 mm clinical margin of normal skin laterally 1
• Include cuff of subdermal fat to allow accurate Breslow thickness measurement 1
• Elliptical incision with long axis parallel to skin lines to facilitate re-excision if needed 1
• Shave and punch biopsies are contraindicated as they make pathological staging impossible 1

Incisional biopsy is occasionally acceptable only for lentigo maligna on the face or acral melanoma, but has no place in primary care 1. One study suggests potential adverse effects for head and neck lesions 1.

For Suspected Basal Cell Carcinoma

Biopsy must include deep reticular dermis when the lesion appears more than superficial, as infiltrative histology may be present only at deeper margins and superficial biopsies frequently miss this component 1.

Urgent Referral Criteria

Patients with melanoma-suspicious lesions require urgent specialist referral to a dermatologist or surgeon with expertise in pigmented lesions, with systems ensuring evaluation within 2 weeks of referral 1.

Immediate specialist referral is mandatory for any lesion removed by a general practitioner subsequently reported as melanoma 1.

Histopathology Requirements

The pathology report must include 1:

• Breslow thickness in millimeters (maximum tumor thickness) 1, 2
• Clark level of invasion (I-V) 1, 2
• Presence and extent of ulceration 1, 2
• Presence and extent of regression 1, 2
• Surgical margin clearance status for both invasive and in situ components 1, 2
• Histological type and special variants 1

Processing by an experienced pathology institute following WHO classification is mandatory 1, 2.

Common Pitfalls to Avoid

• Never perform prophylactic excision of small congenital nevi or clinically benign lesions without suspicious features 1
• Avoid superficial biopsy techniques that compromise staging—misdiagnosis leads to statistically significant treatment delays (6.2 vs 10.7 weeks for BCC, 3.7 vs 9.5 weeks for SCC) and increased incomplete excision rates 4
• Do not rely on visual inspection alone when dermoscopy expertise is available, as this misses 16-34% of melanomas that dermoscopy would detect 3
• Maintain low threshold for biopsy in high-risk populations (prior skin cancer, immunosuppression, genetic syndromes) as clinical assessment is particularly difficult in these patients 1

High-Risk Patient Surveillance

Patients with prior melanoma or atypical mole syndrome require education on melanoma recognition and monthly self-examination 1. Patients with giant congenital pigmented nevi require long-term follow-up due to increased melanoma risk 1.

Genetic counseling referral is indicated for families with three or more melanoma cases, or two cases if one had multiple primaries or atypical mole syndrome 1.