Malignant melanoma (pigm./amelanot.)

Black skin cancer, melanoma, malignant melanoma.

Malignant, epithelial tumour of the melanocytes.

• Incidence (Central Europe): 3-5/100'000/year
• Incidence (Scandinavia): 12-15/100,000/year
• Incidence (Australia): 40/100,000/year
• Lifetime risk (2010) 1:75
• The closer the place of residence to the equator, the higher the incidence (for Caucasians)
• African Americans have a 20-fold lower risk.
• Approximately 1.3% of all cancer deaths are due to malignant melanoma.
• Women > men.

• Superficial spreading malignant melanoma (SSM)
• Nodular malignant melanoma (NM)
• Acrolentiginous malignant melanoma (ALM)
• Lentigo-maligna melanoma (LMM)
• Mucinous melanoma
• Amelanotic malignant melanoma. Watch out: Any type of melanoma can appear amelanotic.
• Desmoplastic malignant melanoma
• Malignant melanoma with unknown primary tumour
• Occult primary site (uvea, meninges, GI tract, lymph nodes)

• Risk factors
• Melanoma in self-history
• UV radiation (cumulative sun exposure and sunburns)
• Light skin type (mild redness, severe tanning)
• Red hair (4.7 times increased risk vs. black haired)
• Positive family history
• > 100 melanocytic nevi
• ≥5 atypical nevus cell nevi if ≥2 1st degree relatives have melanoma
• Dysplastic nevus syndrome (>5 atypical nevus cell nevi and > 50 inconspicuous nevus cell nevi
• MDM2-SNP309 polymorphism
• BK mole syndrome
• Xeroderma pigmentosum

• An association with Parkinson's disease is discussed

• About 1/3 of all melanomas arise on existing nevus cell nevi. The majority of all melanomas arise de novo

• Predilection sites
  • Women: Face, lower legs
  • Men: upper torso

• Partly reddish, partly bluish, sometimes brown-blackish or not pigmented at all, inhomogeneous, usually progressive in size, irregularly bounded nodules or plaques

• Metastasis: In 2/3 of all cases, first lymphogenic and then haematogenic. However, haematogenous initial metastases are also possible
• Satellite metastases: reddish to skin-coloured nodes, which are grouped up to 2 cm around the primary tumour
• In-transit metastases: Cutaneous or subcutaneous metastases that lie between the primary tumour and the locoregional lymph nodes.
• Hematogenous metastases can occur in all organs, especially lungs, liver, heart, brain, skin or bone

• Anamnesis (self-history, family history, sunburns?)
• Whole body inspection incl. mucous membranes, lymph node status!
• Macroscopy and dermoscopy (Two-Step Algorithm, ABCDE, ugly duckling concept)
• If melanoma is suspected, we recommend immediate referral to our centre in Basel (dermatologie@usb.ch with keyword melanoma excision), we take over the excision within 48h.
• If this is not desired, primary complete excision without safety margin is recommended.
• Take biopsies only in exceptional cases, these do not allow determination of Breslow thickness and may contribute to misdiagnosis.

• Immunohistology
  • Routine diagnostics: S100, MART1 and IMP3
  • Most important marker: MART1 (Melan A)
  • Proliferation marker: MIB1
  • Ev. CD10 overexpression is an indication of poorer prognosis

• Post-excision in practice without sentinel lymph node biopsy is the most common mistake as it alters the lymph node drains.
• Metastasis
• Delay of diagnosis not uncommon especially in acral melanoma

• Sun protection (behavioural, topical, textile)
• Regular full body examination

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2. Larson AR, Rothschild B, Walls AC, et al. Impact of the 2009 AJCC staging guidelines for melanoma on the number of mitotic figures reported by dermatopathologists at one institution. J Cutan Pathol 2015;42:536-41.
3. Nathan P, Cohen V, Coupland S, et al. Uveal Melanoma UK National Guidelines. Eur J Cancer 2015;51:2404-12.
4. Watts CG, Dieng M, Morton RL, Mann GJ, Menzies SW, Cust AE. Clinical practice guidelines for identification, screening and follow-up of individuals at high risk of primary cutaneous melanoma: a systematic review. Br J Dermatol 2015;172:33-47.
5. Pflugfelder et al. Malignant melanoma S3-guideline "diagnosis, therapy and follow-up of melanoma". J Dtsch Dermatol Ges. 2013 Aug;11 Suppl 6:1-116, 1-126.