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Melanoma

Essentials

  • Any suspicious naevus can be removed in primary health care.
  • Melanoma should be suspected if a pre-existing naevus (mole) on the skin increases in size, changes colour, bleeds or discharges purulent material. The presence of so-called ”satellite lesions” are also suggestive of melanoma. Melanoma may also develop on a previously healthy skin or mucous membrane.
  • A changed lesion suspected to be melanoma must be excised as soon as possible for an accurate histopathological diagnosis. If it is not possible to remove the lesion as a whole, a biopsy can be taken. Biopsy does not worsen the prognosis.

Epidemiology and risk factors

  • The incidence of new melanomas is on the increase.
  • Exposure to ultraviolet radiation through sunlight is the major risk factor.
  • Melanoma cannot be excluded based on clinical presentation alone (pictures ), and it may develop on a previously healthy looking skin. The specificity of clinical checklists designed to detect the presence of melanoma can be fairly good, but their sensitivity is limited Differential Diagnosis of Mole and Melanoma.

Prevention Statins and Fibrates for Preventing Melanoma

  • Preventive measures seek to reduce the effects of UV radiation.
  • The risk of melanoma transformation in a stable pigmented naevus is too rare to justify prophylactic removal of naevi in patients with numerous naevi.

Lesions suspected to be melanoma Diagnostic Accuracy of Dermatoscopy in Detecting Malignant Melanoma

  • See pictures .
  • Melanoma should be suspected if a naevus
    • has clearly increased in size or changed colour (pictures )
    • is exceptionally large (picture )
    • is surrounded by satellite lesions
    • occurs on the site of a previously removed melanoma.
  • The suspicious naevus should be removed without delay, or the skin change biopsied, in primary health care.
  • Wide excision margins have not been shown to affect survival rates and they probably do not affect the risk of local recurrence either Excision Margin for Malignant Melanoma.
  • A dysplastic melanocytic naevus is treated with normal excision (a margin of 1-5 mm is sufficient). Other treatments, investigations or follow-up are not required if the naevus was completely removed, i.e. it did not reach the excision margin.
    • If the patient has the dysplastic naevus syndrome with several atypical naevi, the follow-up visits should be arranged to a dermatologist if feasible.

Initial stage management

  • If the pathology report confirms melanoma, the patient must urgently be referred to a surgeon for follow-up treatment.
  • If primary melanoma was confirmed by biopsy, the area will need to be excised more radically and a sentinel lymph node biopsy carried out. No other imaging or laboratory investigations are routinely carried out at the time of surgery or during the later follow-up period. High risk patients are an exception and may require individual monitoring under specialist care.

Surgery for melanoma

  • The surgery involves removing more skin and subcutaneous tissue around the tumour. The extent of the excision is dependent on the site of the tumour, its thickness (Breslow scale) and the extent of infiltration (Clark scale).
  • Very superficial melanomas (Breslow ≤2 mm) are excised with a 1 cm margin of healthy tissue. If the melanoma is thicker, the scar left after an earlier excision of the melanoma, or the whole biopsied melanoma, is excised with a margin of 2 cm and the subcutaneous fat down to the fascial level.
  • The excision is performed along the skin folds, except in the extremities where it is performed parallel to the longitudinal axis (and lymph channels) of the extremity, which allows direct closure of the wound.
  • The majority of patients will undergo a sentinel node biopsy in order to establish the extent of the disease.

Drug treatment

  • Drug treatment of melanoma consists either of
    • adjuvant treatment which aims to reduce the recurrence of high risk melanoma, or
    • pharmacological treatment of advanced disease.
  • Factors that would predict the efficacy of different oncological treatments are not well known in melanoma.
  • There are no standardised protocols for adjuvant treatment.
  • Cytotoxic drugs have not been shown to be beneficial in adjuvant treatment.
  • Immunotherapy, BRAF/MEK inhibitors or radiotherapy may be used as adjuvant therapy, as necessary.

Advanced melanoma

Locally advanced melanoma

  • The involvement of the sentinel lymph node is the strongest single prognostic factor in deep melanomas and in those of intermediate thickness.
  • Sentinel lymph node examination is usually performed in patients who are diagnosed with a ≥0.8 mm thick melanoma that shows other features of activity, e.g. ulceration.
  • If the sentinel node biopsy shows metastatic involvement, evacuation of the lymph node region in question can be carried out either during or after the primary surgery, or the patient may only be followed up. Specific local guidance may be available regarding the indications for the evacuation of the lymph node region.
  • All patients with metastasis in the sentinel node and/or other regional lymph nodes must be referred to an oncologist. These patients will undergo imaging studies and have an individual treatment or follow-up programme at discretion.
  • Locally advanced melanoma is characterised by local recurrences in the scar, satellite lesions or in-transit metastases as well as regional lymph node metastases. The management of all these involves surgical excision.
  • If the patient has palpable lymph nodes and there is a clinical suspicion of melanoma spreading into regional lymph nodes, an ultrasound examination and a fine needle biopsy should be carried out before surgical excision and possible sentinel node examination. If these investigations reveal metastases, a full-body CT or PET/CT scan is usually performed before the evacuation of lymph nodes.

Metastatic melanoma

  • Individual treatment planning is needed for melanoma with distal metastases.
    • If melanoma has spread only to the regional lymph nodes they must be removed surgically (see above).
    • Metastasectomy may be an option for patients with isolated distal metastasis.
    • Results have been achieved, even in terms of increasing life expectancy, with new drugs (ipilimumab, nivolumab, pembrolizumab, vemurafenib, dabrafenib, trametinib, encorafenib, binimetinib) also in the treatment of widespread melanoma, although the treatment in principle still remains palliative.

Follow-up of a patient with melanoma

  • The follow-up focuses on detecting possible skin or lymph node recurrences as well as new primary tumours. The patient is taught techniques of self examination.
  • Follow-up appointments should be made every 6-12 months until 5 years have lapsed from the diagnosis. The follow-up of a patient with advanced melanoma is individually planned. The venue of the follow-up appointments is decided locally. It is desirable that the patient is always seen by the same doctor.
  • If the patient has numerous moles or dysplastic naevus syndrome, a hereditary condition, the follow-up of melanoma should be carried out at a skin clinic. Good quality photographs facilitate follow-up.
  • During a follow-up examination, the patient's general health and symptoms should be checked, and the site where melanoma was removed and regional lymph nodes should be palpated. Imaging studies are not routinely needed.
    • Melanoma satellites often appear as subcutaneous lumps and are seen as dark spots under the skin. The first sites of metastasis may be the regional lymph nodes, which must be closely monitored by palpating and by ultrasonography if needed.
    • If clinical examination is suggestive of advanced melanoma, the following investigations are recommended: basic blood count with platelet count, ALT, chest x-ray and either an ultrasound examination of the liver or full-body CT or PET/CT scanning.

Pictures

Evidence Summaries ⬆