P03.013 Malignant melanoma

Malignant melanoma, the most aggressive form of skin cancer, arises from melanocytes, pigment-producing cells in the skin. Early diagnosis and prompt treatment are crucial for improving prognosis. This guide summarizes key points for PLAB UK students regarding malignant melanoma.

Risk Factors:

• Sun exposure: Ultraviolet (UV) radiation from sunlight is the major risk factor. A history of sunburn, particularly in childhood, and intense intermittent sun exposure increase the risk.
• Sunburns: Blistering sunburns are particularly concerning.
• Fair complexion: Individuals with light skin, red or blonde hair, and blue or green eyes have a higher risk.
• Melanocytic nevi (moles): A high number of moles (>50) and atypical moles (dysplastic nevi) increase the risk.
• Family history: Having a first-degree relative with melanoma increases the risk.

Clinical Features:

• ABCD rule: This mnemonic helps identify suspicious lesions:
  • Asymmetry: One half of the mole is unlike the other.
  • Border irregularity: The edges are uneven or scalloped.
  • Color variation: The mole has different shades of brown, black, red, white, or blue.
  • Diameter: The mole is larger than 6 millimeters (about the size of a pencil eraser).
• Other features: Rapid growth, bleeding, ulceration, or itching can also be warning signs.

Diagnosis:

• Clinical examination: A thorough skin examination is essential, focusing on pigmented lesions and areas of sun damage.
• Dermoscopy: A handheld device with magnification and illumination can aid in visualizing features suggestive of melanoma.
• Skin biopsy: A definitive diagnosis requires a biopsy, where a small tissue sample is removed and analyzed under a microscope.

Management:

• Surgical excision: The primary treatment involves complete surgical removal of the tumor with clear margins. Sentinel lymph node biopsy may be performed to assess lymph node involvement.
• Adjuvant therapy: In some cases, depending on the stage and thickness of the melanoma, adjuvant therapy with medications (immunotherapy) may be recommended to reduce the risk of recurrence.
• Advanced melanoma: For advanced stages with metastasis, treatment options include targeted therapy, immunotherapy, and palliative care.

Exam Keep Points:

• Remember the ABCD rule for identifying suspicious lesions.
• Be familiar with the risk factors for malignant melanoma.
• Understand the importance of early diagnosis and prompt surgical excision.
• Be aware of adjuvant therapy options for high-risk melanoma.

Prognosis:

The prognosis of malignant melanoma depends on the stage at diagnosis. Early detection and treatment significantly improve the chances of a cure.

Additional Resources:

• National Institute for Health and Care Excellence (NICE): https://www.nice.org.uk/guidance/ng14
• British Association of Dermatologists: https://www.bad.org.uk/referrals/melanoma/