Melanoma

• Melanoma


  A type of skin cancer that develops in the skin cells called melanocytes and usually occurs on the parts of the body that have been overexposed to the sun
• In 2021, 106,000 new melanoma cases were diagnosed in the U.S. and over 7000 people died of this disease
• Melanoma is more common in men
• Melanoma is much more common in Whites (17.2 per 100,000 White men) than in African Americans (1 per 100,000 African American men)
• Increased risk factors for developing melanomas

  • Fair skin
  • Red hair
  • Light eyes
  • Abundance of freckles
  • Atypical moles
  • Large amount of moles (>50)
  • Personal history of any skin cancer
  • Family history of melanoma
• Melanoma is the leading cause of death from skin cancer. Although it represents <10% of all skin cancers, it accounts for at least 70% of deaths related to skin cancer
• The median age at diagnosis is 53 yr
• Risk factors for developing melanoma

  • High recreational/intermittent sun exposure
  • History of blistery sunburns in childhood or adolescence
  • Exposure to artificial ultraviolet radiation from use of tanning beds
• Types of melanoma


  • Superficial spreading melanoma (70%)
  • Nodular melanoma (15%-30%)
  • Lentigo maligna (10%-15%)
  • Acral lentiginous (<5%)
• Superficial spreading melanoma


  • Slow radial growth phase
  • Flat during early phase, macule or papule in late stage
  • More common in women
• Nodular melanoma


  • Rapid vertical growth
  • Papule or nodule
  • More common on trunk, head, face
• Lentigo maligna


  • Chronically sun-damaged skin
  • Slow radial growth, confined to the epidermis for many years
  • Large macule, arises in a preexisting nevus
  • More common in the elderly
  • More common on face, neck, arms
• Acral lentiginous


  • Slow radial growth phase with vertical phase later on
  • Large dark patch, arising in a preexisting lesion
  • More common in Asians and African Americans
  • Occurs on soles, palms, beneath nail beds (subungual)
• Dermoscopy


  Use of an instrument that shines polarized light on skin surfaces and magnifies skin lesions, can increase the accuracy in diagnosing melanoma by 10% to 27%
• Dermoscopic features


  • Irregularity in the border of the lesion
  • Multiple colors
  • Presence of blood vessels
  • Changes in the texture of the lesion
• Biopsy


  1. Excisional biopsy with elliptical excision that includes 1 to 2 mm of normal skin surrounding the lesion and extends to the subcutaneous tissue

  2. Incisional punch biopsy sometimes necessary in surgically sensitive areas (e.g., digits, nose)
• Breslow depth


  Measurement in millimeters of the tumor depth from the granular layer of the epidermis to the base of the melanoma, the most important prognostic indicator for melanomas
• Sentinel lymph node excision (SLNE)


  1. Use of radiologic lymphoscintigraphy to map lymphatic drainage from the site of the primary melanoma to the first sentinel lymph node in the region

  2. The most important staging and potentially prognostic procedure for patients with melanoma
• Sentinel lymph node excision (SLNE) should be considered in patients with intermediate (1 to 4 mm) melanomas
• Other tests


  • CT scan
  • PET scan
  • MRI
  • Blood chemistry test (LDH level)
• Re-excision of the involved area after histologic diagnosis

  1. For melanoma in situ, margin should be 5 mm

  2. Breslow depth up to 1 mm, the recommended surgical margin is 1 cm

  3. Tumor thickness >1 mm and <4 mm, 2-cm excision margin is recommended

  4. Melanomas >4 mm, a 2 cm margin is recommended
• Sentinel lymph node excision is recommended in all patients with melanoma greater than 1 mm in depth or ulcerated melanomas greater than 0.8 mm
• Complete lymph node dissection is recommended for patients who present with palpable lymph nodes at the time of diagnosis
• 1. yr survival related to melanoma thickness

  • Breslow depth up to 1 mm: 95%
  • Breslow depth 1.01-2 mm: 85%
  • Breslow depth 2.01-4 mm: 70%
  • Breslow depth >4 mm: 50%
• The 5-yr survival in patients with distant metastasis was historically <10% but is improving with current therapeutic options and is now >20% and with combination immunotherapy is approaching 50%
• Treatment of advanced melanoma

  • Surgical excision
  • Lymph node dissection
  • Chemotherapy
  • Immunotherapy
  • Radiation therapy
• Melanoma is a 32-year-old female with a mole
• Sentinel lymph node

  The first lymph node that drains fluid from a tumor
• Intermediate melanomas

  Melanomas that are between 1 and 4 mm thick
• Radioactive tracer

  A substance used to identify the sentinel lymph node(s) that drain the tumor area