What are the steps for identifying and managing melanoma?

Identification of Melanoma

Identify melanoma using the ABCDE criteria combined with the "ugly duckling" sign, followed by complete excisional biopsy for histopathological confirmation. 1

Clinical Recognition

Primary Diagnostic Criteria: ABCDE Rule

Suspicious pigmented lesions are characterized by the following features 1:

• A (Asymmetry): One half of the lesion does not match the other half 1
• B (Border irregularities): Edges are ragged, notched, or blurred 1
• C (Color heterogeneity): Multiple colors or uneven distribution of pigment 1
• D (Diameter/Dynamics): Traditionally >6 mm, though many primary melanomas today have a diameter <5 mm 1
• E (Evolution): Recent changes in color, elevation, or size 1

Important caveat: The diameter criterion is increasingly less reliable, as contemporary melanomas are frequently detected at <5 mm. 1 This reflects earlier detection but means clinicians cannot rely on size alone to exclude melanoma.

The "Ugly Duckling" Sign

The "ugly duckling" concept is a critical complementary approach: nevi in the same individual tend to resemble one another, and melanomas often stand out as different from the patient's other lesions. 1 This comparative pattern recognition may be more effective than isolated ABCD criteria analysis, as dermatologists unconsciously rely more on overall pattern assessment than individual morphologic criteria. 2

Enhanced Diagnostic Accuracy with Dermoscopy

Dermoscopy performed by an experienced physician significantly enhances diagnostic accuracy and should be used when available. 1, 3 However, this technique requires proper training and experience to be effective. 1

Physical Examination Requirements

A complete skin examination is mandatory when evaluating a suspicious lesion 1:

• Examine all pigmented lesions across the entire body surface
• Document the site and size of the suspicious lesion 1
• Look specifically for tumor satellites and in-transit metastases 1
• Palpate regional lymph nodes for adenopathy 1
• Assess for hepatomegaly in higher-risk cases 1

Biopsy Technique: The Definitive Diagnostic Step

Diagnosis must be based on a full-thickness excisional biopsy with a 2-5 mm margin of normal skin laterally and a cuff of subdermal fat. 1

Critical Technical Points

• Excisional biopsy is mandatory - complete removal of the entire lesion is required 1
• The incision should be elliptical with the long axis parallel to skin lines to facilitate potential re-excision 1
• Shave and punch biopsies are contraindicated as they make pathological staging impossible 1
• Incisional biopsy is rarely acceptable - only for specific situations like lentigo maligna on the face or acral melanoma, and never in primary care 1

Common pitfall: Incomplete biopsies prevent accurate Breslow thickness measurement, which is essential for staging and determining surgical margins. 1

Histopathological Requirements

Processing must be performed by an experienced pathology institute. 1 The histology report should follow the AJCC classification and include 1:

• Maximum thickness in millimeters (Breslow depth) - the single most important prognostic factor
• Mitotic rate 1
• Presence of ulceration 1
• Presence and extent of regression 1
• Clearance of surgical margins 1
• Clark level of invasion (I-V) 1
• Anatomical site and degree of sun damage 1
• Melanoma subtype (superficial spreading, nodular, lentigo maligna, acrolentiginous) 1

Architectural Features of Malignant Melanoma

Histologically, melanoma demonstrates 4:

• Asymmetry, confluence of growth, and poor circumscription
• Variable nest size and irregular distribution along the basal layer
• Lack of maturation in the dermal component
• Presence of mitotic figures in the dermal component (unusual in benign nevi)
• Melanocytes losing their nesting characteristics with more diffuse distribution

Staging Investigations

For low-risk melanomas (pT1a, <1 mm thickness without ulceration), no additional investigations are necessary. 1

For higher tumor stages (>1 mm or with ulceration), imaging is recommended 1:

• Imaging of regional nodal basins
• Chest/abdomen/pelvis imaging for proper staging 1
• Sonography of abdomen and regional lymph nodes 1

Note: PET scanning is not useful for initial staging of clinically localized melanoma. 1

Molecular Testing Considerations

In cases of metastatic disease only, mutation analysis should be performed 1:

• BRAF mutation testing is mandatory
• Optional NRAS and c-Kit testing
• Testing must be performed in accredited institutes with quality controls 1

Mutational testing of primary tumors without metastases is not recommended. 1

High-Risk Patient Surveillance

Patients at increased risk require specific management 1:

• Those with previous melanoma or atypical mole syndrome should be taught self-examination and monitored regularly 1
• Patients with giant congenital pigmented nevi require long-term follow-up 1
• Individuals with ≥3 family members with melanoma should be referred for genetic counseling 1