Melanoma and melanocytic lesions Flashcards
This 64-year-old lady has had a brown patch on her right cheek for several years. Two months ago she noticed an area of darker pigmentation developing within the centre of the existing lesion. The area also began to itch and bleed.
Which of the following observations about the lesion (image below) are important in diagnosing the lesion?
- Recent change in pigmentation
- Asymmetry of the lesion
- Diameter of the lesion
- Irregularity of borders of the lesion
- Site of the lesion
Look for changes in size, shape, colour of moles, crusting or bleeding. The ABCDE rule for suspicious pigmented lesions is:
- A, asymmetry;
- B for irregular border;
- C for colour variation;
- D for diameter greater than 6mm;
- E for evolution.
- Recent change in pigmentation
- Asymmetry of the lesion
- Diameter of the lesion
- Irregularity of borders of the lesion
What is the most likely diagnosis?
- Squamous cell carcinoma
- Pigmented basal cell carcinoma
- Seborrhaeic wart
- Pigmented naevus
- Melanoma
Asymmetrical, irregular border, variation in colour, diameter larger than 6mm, evolving.
Melanoma
After examining the lesion, what else would you want to examine?
- Cervical lymph nodes
- The mouth
- Facial nerve function
- The remainder of the skin
- Respiratory function
It is crucial to always examine the skin of the patient fully as there may be more lesions – do not forget to look behind ears, between toes and any skin folds.
- The remainder of the skin
- Cervical lymph nodes
What is your next course of action?
- Chemotherapy
- Radiotherapy
- Excisional biopsy
- Regular review in outpatients
- Wide surgical excision
A diagnosis is needed before treatment can be commenced.
Excisional biopsy
Excision biopsy confirms the diagnosis of melanoma. What is the definitive treatment of this lesion?
- Radiotherapy
- Chemotherapy
- Wide surgical excision with reconstruction
- Combined surgery and radiotherapy
- Regular review in outpatients to monitor progress
Wide surgical excision with reconstruction is the definitive treatment.
Which of the following are important prognostic factors for melanoma?
- Diameter of the lesion
- Depth of the lesion in mm
- Longevity of the lesion
- The presence of involved cervical lymph nodes
- The number of layers of the epithelium penetrated by the lesion
The Breslow depth is the depth of the lesion and
Clarke’s level the number of layers of epithelium penetrated
- these are both important prognostic factors as is the presence of involved regional nodes, indicating metastatic spread.
- A Breslow depth of ≤ 0.75mm gives a 90% 5 year survival.
Answer:
- Depth of the lesion in mm
- The presence of involved cervical lymph nodes
- The number of layers of the epithelium penetrated by the lesion
Which of the following is thought to be the most important factor for developing melanoma?
- Sunlight (UV) exposure
- Family history
- Sex of the patient
- Age of the patient
- Site of the lesion
Exposure to UV light is the single most important risk factor for developing malignant melanoma.
- Sunlight (UV) exposure
Which of the following statements about melanoma are true?(4)
- Melanoma is more common in men on the torso
- Melanoma is more common in women on the legs
- Melanoma metastasises by the blood stream and lymphatic systems
- Older patients with melanoma do much worse
- Melanomas are sensitive to radiotherapy
- Prevention (sun protection) is extremely important
The most common sites of melanoma depend on the areas of the body most exposed to the sun (UV light) – torso in men and legs in women.
- Melanoma is more common in men on the torso
- Melanoma is more common in women on the legs
- Melanoma metastasises by the blood stream and lymphatic systems
- Prevention (sun protection) is extremely important
Define melanoma.
Melanoma is a malignant tumour arising from melanocytes. It is among the most common forms of cancer in young adults and typically presents as a new or changing deeply pigmented skin lesion.
How common are melanomas?
Incidence increasing
US lifetime risk is 1 in 35
Third most common skin cancer - but most common cause of skin cancer-related death. 20% develop metastatic disease.
What is the aetiology of melanoma?
Arises from melanocytes which are pigment producing cells found in the skin, eye and CNS.
Genetic factors - fair skin, susceptibility to sunburn, melanoma-related genes e.g CDKN2A or DNA repair defects in xeroderma pigmentosum.
Environmental factors - solar and artificial UV, proximity to equator.
What % of melanomas arise from pre-existing naevi (moles)?
25-42%
Name 3 different subtypes of melanoma.
- Superficial spreading melanoma (most common - 60-70%)
- Nodular melanoma (any site)
- Lentigo maligna melanoma (head and neck in elderly)
- Acral lentiguous melanoma (in darker skin, palms, soles and nails)
Where does superficial spreading melanoma most commonly arise in men and women?
- Men - torso
- Women - legs
What type of melanoma growth pattern is more dangerous?
- Melanoma can grow by radial or vertical growth
- Vertical growth is more likely to result in involvement of the vasculature/lymphatics –> metastasis
Apart from the ABCDE tool for diagnosis of melanoma, what other criteria can be used?
Glasgow 7 point checklist is found on each 2WW referral form for dermatology - 3 points warrants referral.
What is Hutchinson’s sign?
In the setting of pigmented bands in the nail bed and matrix (melanonychia striata), this sign shows extension of pigment into the proximal or lateral nail fold.
What is lentigo maligna?
Lentigo maligna melanoma is a type of invasive skin cancer. It develops from lentigo maligna, which is sometimes called Hutchinson’s melanotic freckle.
Lentigo maligna stays on the outer surface of the skin. When it starts growing beneath the skin’s surface, it becomes lentigo maligna melanoma.
What 2 histological criteria are used in assessment of the biopsy?
- Breslow’s thickness - good for assessing all melanomas (even the thicker ones) - from granular to bottom.
- Clark’s level - tumour thickness but less accurate than Breslow. Only good for the thinnest types of melanomas of the dermis and epidermis.
What is the ugly duckling sign?
Sign for picking out melanoma - will usually look like the odd naevi out
What are the treatment options for melanoma?
