Malignant Melanoma

Question 1

What is Melanoma?

Answer 1

• An invasive malignant tumour of the epidermal melanocytes
• Has the potential to metastasise

Question 2

What are the suspicious features of Melanoma?

Answer 2

• Asymmetrical shape
• Border (irregular)
• Colour alterations ( more than one colour
• Diameter >6mm
• Evolving lesion - change in size/shape
• Symptoms (bleeding and itching)

Question 3

What are the Risk Factors for Melanoma?

Answer 3

• UV exposure (severe burn in childhood)
• Fitzpatrick Skin type 1
• History of >100moles
• Family History
• Genetic Mutations
• Immunosuppression

Question 4

What is the Pathophysiology of Melanoma?

Answer 4

• Uncontrolled Proliferation of Melanocytes
• Melanocytes are found within the basal epidermis and melanin is transferred to the keratinocytes with protects the nucleus from UV damage

Question 5

What is the Typical Tumour Progression?

Answer 5

• Benign Naevus (typical mole)
• Dysplastic Naevus (atypical mole)
• Radial Growth Phase ( Extend superficially and outwards initially)
• Vertical Growth Phase ( Malignant cells invade the basement membrane and proliferate downwards into the dermis)
• Metastasis (Malignant cells spread to other areas of body - lymph nodes, skin/soft tissue, solid organs (lungs, liver, bone and brain)

Question 6

What are the different types of Melanoma?

Answer 6

• 1. Superficial Spreading Melanoma - commonly seen on the lower limbs, young/middle-aged adults - UV exposure
• 2. Nodular Melanoma - commonly seen on trunk in young and middle ages adults
• 3. Lentigo Maligna Melanoma - commonly seen on the face, in the elderly
• 4. Acral lentiginous Melanoma - commonly seen on the palms, nails beds and palmar/plantar surface of hands and feet
     -5. Desmoplastic Melanoma - very rare melanoma - abnormal deposits of collagen are present

Question 7

What is involved in the Histology of a Melanoma?

Answer 7

• Clark Level (1-4) - estimated prognosis based upon the anatomical level of invasion into the skin
• Breslow thickness - the vertical thickness of the tumour in milllimetres
• Ulceration - presence or absence of ulceration, ulceration = poorer prognosis
• Mitotic Index ( looks at cell turnover)

Question 8

What investigation would you consider doing?

Answer 8

• History and Examination (including lymph nodes)
• FNA and cytology for lymph nodes
• Total body CT or PET-CT
• LDH (lactate dehydrogenase)

Question 9

How do you stage Melanoma?

Answer 9

• TNM
• AJCC cutaneous melanoma staging guidelines

Question 10

What is the Surgical managment of Melanoma?

Answer 10

• Wide Local Excision (WLE) - standard treatment for primary melanoma
• Sentinel Lymph Node Biopsy as a staging tool - If positive SLNB = regional lymphatics are removed

Question 11

What is the Medical managment of Melanoma?

Answer 11

• Electrochemotherapy - treats melanoma metastases in the skin using pulses of electricity with chemotherapy
• Adjuvant: Chemotherapy, Radiotherapy, Immunotherapy

Question 12

What is the margin of excision for a 0-1mm lesion?

Answer 12

• 1cm

Question 13

What is the margin of excision for a 1-2mm lesion?

Answer 13

• 1-2cm

Question 14

What is the margin of excision for a 2-4mm lesion?

Answer 14

• 2-3cm

Question 15

What is the margin of excision for a 4mm lesion?

Answer 15

• 3cm