Makindo Medical Notes

Related Subjects: |Nikolsky's sign |Koebner phenomenon |Erythema Multiforme |Pyoderma gangrenosum |Erythema Nodosum |Dermatitis Herpetiformis |Lichen Planus |Acanthosis Nigricans |Acne Rosacea |Acne Vulgaris |Alopecia |Vitiligo |Urticaria |Basal Cell Carcinoma |Malignant Melanoma |Squamous Cell Carcinoma |Mycosis Fungoides (Sezary Syndrome) |Xeroderma pigmentosum |Bullous Pemphigoid |Pemphigus Vulgaris |Seborrheic Dermatitis |Pityriasis/Tinea versicolor infections |Pityriasis rosea |Scabies |Dermatomyositis |Toxic Epidermal Necrolysis |Stevens-Johnson Syndrome |Atopic Eczema/Atopic Dermatitis |Psoriasis

⚠️ If you find a lesion suspicious for melanoma → always check local lymph nodes, examine the liver, and refer urgently to a specialist.

📖 About

• Malignant melanoma is the most lethal skin cancer, causing ~1,500 deaths annually in the UK.
• Early diagnosis is crucial → early-stage melanoma has a 95% cure rate, but survival drops sharply with late presentation.
• Incidence is rising 📈, and ~50% of melanomas arise in normal skin (not pre-existing moles).

🧬 Aetiology

• Originates from melanocytes, capable of rapid spread to lymph nodes and distant organs.
• Many arise de novo, others from pre-existing moles.
• Melanocytes also exist in eyes, ears, GI tract, leptomeninges, mucous membranes → all potential sites.

⚡ Risk Factors

• Family history of melanoma 👨‍👩‍👧
• Fair skin, freckles, easy sunburn ☀️
• Excessive UV exposure, especially severe childhood sunburns
• >50 moles or dysplastic nevus syndrome
• Atypical / congenital naevi
• Older age
• Xeroderma pigmentosum (rare, extreme UV sensitivity)

👀 Clinical Presentation

• Suspicious pigmented or nodular lesion – use the **ABCDE rule** below.

🔍 ABCDE Rule for Self-Examination

• A – Asymmetry: one half ≠ the other
• B – Border: irregular, ragged, blurred
• C – Colour: variegated (brown, black, pink, blue, red)
• D – Diameter: >6 mm
• E – Evolution: changes in size, shape, bleeding, elevation

📏 Breslow’s Depth & Prognosis

• Breslow’s Depth: distance from epidermal granular layer → deepest tumour invasion.
• 5-year survival by depth:
  • <0.5 mm → 100%
  • 0.6–1.0 mm → 98%
  • 1.1–1.5 mm → 90%
  • 1.6–2.0 mm → 80%
  • 2.1–3.0 mm → 60%
  • >3.0 mm → 50%

📉 Additional Poor Prognostic Factors

• Ulceration
• High mitotic rate
• Trunk lesions
• Male sex

🧾 Subtypes of Melanoma

• Superficial spreading → 70% of cases
• Nodular → 15%, often de novo, aggressive 🚨
• Lentigo maligna → 10%, elderly, sun-damaged skin
• Acral lentiginous → 5%, palms/soles, more common in darker skin

🔬 Investigations

• Wide local excision (WLE) & biopsy for Breslow depth
• Staging if >1 mm
• Tests for spread:
  • LFTs (liver mets)
  • Biopsy of enlarged nodes
  • Lymphoscintigraphy → sentinel node
  • LDH, CT/MRI, CXR, ultrasound

📊 Staging (AJCC simplified)

• Stage I: in situ / ≤1 mm
• Stage II: 1–4 mm (± ulceration)
• Stage III: regional nodes / satellite lesions
• Stage IV: distant mets (lung, liver, brain, bone)

💊 Management

• Wide Local Excision: margin guided by Breslow depth
• Sentinel Node Biopsy: if >1 mm or palpable nodes
• Advanced Disease:
  • Interferon alpha-2B (rare now, high toxicity)
  • Chemotherapy (dacarbazine) – limited efficacy
  • Immunotherapy (see below)

🛡️ Immunotherapy

• Ipilimumab (CTLA-4 inhibitor) – infusion q3w × 4
• Nivolumab (PD-1) – q2w
• Pembrolizumab (PD-1) – q3w
• Talimogene laherparepvec – intratumoural injection

🎯 Targeted Therapy

• BRAF V600 mutation (~50% cases):
  • Vemurafenib + cobimetinib
  • Dabrafenib + trametinib
  • Trametinib (MEK inhibitor)

☢️ Radiotherapy & Chemo

• Radiotherapy → adjuvant after nodal surgery or palliation
• Chemotherapy → rarely used, superseded by modern agents

🧪 Vaccines

• Experimental; available only in clinical trials

✅ Conclusion

• Early recognition & excision are the only curative measures.
• Advanced disease → immune checkpoint inhibitors & BRAF/MEK inhibitors have transformed prognosis.
• Prevention (UV avoidance, education) remains key 🌞🕶️.