• 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
  • A noninvasive technique using a magnifying device to visualize diagnostic features of pigmented lesion
    • Enhances diagnostic accuracy & leads to performance of a 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
    • Based on the 2010 American Joint Committee on Cancer TNM definitions for melanoma
      • Primary Tumor (T)
        • TX:  Primary tumor unassessable
        • T0:  No evidence of primary tumor
        • Tis : : Melanoma in situ
        • T1a: <1.0 mm thickness w/o ulceration & <1 mitosis/mm2
        • T1b: <1.0 mm thickness w/ ulceration or ≥1 mitosis/mm2
        • T2a: 1.01-2.0 mm thickness w/o ulceration
        • T2b: 1.01-2.0 mm thickness w/ ulceration
        • T3a: 2.01-4.0 mm thickness w/o ulceration
        • T3b: 2.01-4.0 mm thickness w/ ulceration
        • T4a: >4.0 mm thickness w/o ulceration
        • T4b: >4.0 mm thickness w/ ulceration
    • 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
    • Based on the 2010 American Joint Committee on Cancer Anatomic Stage and Prognostic Groups
      • Clinical Staging3
        • Stage 0:
          • Tis N0 M0
        • Stage IA:
          • T1a N0 M0
        • Stage IB:
          • T1b N0 M0; T2a N0 M0
        • Stage IIA:
          • T2b N0 M0; T3a N0 M0
        • Stage IIB:
          • T3b N0 M0; T4a N0 M0
        • Stage IIC:
          • T4b N0 M0
        • Stage III:
          • Any T >N1 M0
        • Stage IV:
          • Any T Any N M1
      • Pathologic Staging4
        • Stage 0
          • Tis N0 M0
        • Stage IA
          • T1a N0 M0
        • Stage IB
          • T1b N0 M0;  T2a N0 M0
        • Stage IIA
          • T2b N0 M0 T3a; N0 M0
        • Stage IIB
          • T3b N0 M0 T4a; N0 M0
        • Stage IIC
          • T4b N0 M0
        • Stage IIIA
          • T1-4a N1a M0
          • T1-4a N2a M0
        • Stage IIIB
          • T1-4b N1a M0
          • T1-4b N2a M0
          • T1-4a N1b M0
          • T1-4a N2b M0
          • T1-4a N2c M0
        • Stage IIIC
          • T1-4b N1b M0
          • T1-4b N2b M0
          • T1-4b N2c M0
          • Any T N3 M0
        • Stage IV
          • Any T Any N M1
      1Micrometastasis is diagnosed after biopsy of sentinel lymph node (SLN)
      2Macrometastasis is defined as nodal metastasis detected clinically & confirmed pathologically
      3Clinical staging includes primary melanoma microstaging & clinical &/or radiologic metastatic evaluation
      4Pathologic staging includes primary melanoma microstaging & regional LN pathologic information after partial or total lymphadenectomy