Symptoms

Suspicious lesions are assessed by examining the entire skin surface including nevi
- ABCDE mnemonic is utilized in characterizing lesions, eg asymmetry, border irregularities, color changes, diameter & evolution
- “Ugly duckling” concept: Melanotic lesions have a different appearance from the surrounding nevi

Dermoscopy

A noninvasive technique using a magnifying device to visualize diagnostic features of pigmented lesion
- Enhances diagnostic accuracy & leads to performance of a biopsy

Biopsy

A full-thickness, narrow, excisional biopsy should be the basis of diagnosis
- Wide surgical margins may affect accuracy of succeeding lymphatic mapping
- An experienced pathologist should examine the specimen for microstaging [a staging technique determined histologically by the Breslow classification (vertical thickness of lesion) & the Clark classification (anatomic level of invasion)]
Various biopsy methods exist, eg incisional, punch, elliptical or broad shave; however, chosen method should be able to obtain an adequate specimen for a definitive diagnosis or exclusion of melanoma
- Partial sampling or incisional biopsy can be performed on facial, acral, or large lesions & in uncertain diagnosis or low clinical suspicion
- Broad shave biopsy for lentigo maligna melanoma in situ
- Fine-needle aspiration may be done for confirmation of lymph node involvement in stage III & IV disease & of initial clinical recurrence
Pathology report should include the maximum histologic depth of lesion (Breslow thickness), ulceration, Clark level (optional for tumors >1 mm), mitotic rate, & peripheral & deep margins
- Other histologic features reported include satellitosis, vertical growth phase, tumor-infiltrating lymphocytes, dermal regression, angiolymphatic invasion, histologic subtypes, neurotropism, & desmoplasia
Repeat biopsy may be performed if specimen was inadequate for diagnosis or microstaging

Alternative Diagnosis

Several diseases may present similarly as melanoma & thus have to be excluded: Atypical moles, blue nevi, venous lakes, seborrheic keratoses, warts w/ focal thromboses, basal & squamous cell carcinomas, dermatofibromas, hematomas, & pyogenic granulomas

Preliminary workup includes a thorough medical history & physical examination
- A detailed history should include an evaluation of melanoma-related risk factors & review of systems paying attention to skin, lymphatic, neurologic, pulmonary, gastrointestinal, & musculoskeletal systems
- Physical examination (PE) should be focused on a complete examination of the skin & lymph nodes
Staging studies may include lab tests (CBC, LDH, liver function tests) & imaging procedures (chest x-ray, CT & PET scans, MRI, & nodal ultrasound)
- In asymptomatic patients w/ newly diagnosed melanoma of any thickness, baseline lab tests & imaging studies are generally not advised; may be performed if clinically indicated based on patient’s signs & symptoms
- Workup is unnecessary in low-risk melanoma; however, imaging is recommended in higher stages of melanoma for proper staging
- Baseline imaging may be considered if sentinel lymph node biopsy is positive, recommended in clinically positive nodes and in-transit metastases or recurrence
- Ultrasound of the nodal basin may be considered if PE of regional LN is uncertain; histologic confirmation should be done if w/ abnormal results
Genetic mutation testing may be performed if targeted therapy is being considered for the patient or if it is pertinent for candidacy in clinical trials
- Routine genetic testing is not encouraged on primary localized melanomas

Sentinel Lymph Node Biopsy (SLNB)

A minimally invasive microstaging technique that has become a staging standard for cutaneous melanoma
- Considered the most specific & sensitive staging technique for detection of micrometastases in LN
- Performance of SLNB may depend on presence of comorbidities or patient preference
Biopsies the node that immediately drains the primary tumor
- Identifies nodal metastasis
- Identifies patients who may need lymph node dissection & patients who may gain from adjuvant therapy
Should be done before wide excision of the lesion for accurate lymphatic mapping
Not recommended for melanoma in situ or T1a melanoma
Generally not considered w/ tumor thickness <0.75 mm, though it may be done in high-risk patients or if microstaging result is uncertain
Should be discussed w/ patient if tumor thickness is 0.76-1 mm
Recommended in intermediate-thickness (1-4 mm) & thick (>4 mm) melanomas

TNM Classification

Developed by the American Joint Committee on Cancer (AJCC)
It details tumor thickness, degree of lymph node involvement, & metastatic spread
- Information provided helps determine treatment, follow-up, & prognosis of patient

Regional Lymph Nodes (N)
- NX: Regional lymph nodes unassessable
- N0: No detectable regional metastases
- N1a: 1 metastatic node w/ micrometastasis¹
- N1b: 1 metastatic node w/ macrometastasis²
- N2a: 2-3 metastatic nodes w/ micrometastasis¹
- N2b: 2-3 metastatic nodes w/ macrometastasis²
- N2c: 2-3 metastatic nodes w/ in-transit metastases/satellites w/o metastatic nodes
- N3: ≥4 metastatic nodes, or matted nodes, or in-transit metastases/satellites w/ metastatic nodes

Distant Metastasis (M)
- M0: No distant metastasis
- M1a: Distant skin, subcutaneous, or nodal metastases w/ normal serum LDH
- M1b: Lung metastases w/ normal serum LDH
- M1c: All other visceral metastases w/ normal serum LDH or any distant metastases w/ elevated serum LDH

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