DERM - Skin Cancers/Lesions

Question 1

Malignant Melanoma

Pathophysiology 
Risk Factors
Classification
ABCDE Signs
Management

Answer 1

1. ) Pathophysiology - malignant tumour arising from melanocytes in the skin
   - least common but lowest survival (90%- 5y)
   - lymphatic spread to breast, lung, colon, liver, bone
2. ) Risk Factors
   - ↑age, PH/FH of skin cancer, atypical moles (naevi)
   - pale skin, burns easily, light-coloured eyes/hair,
   - h/o of sunburn, UV exposure e.g. indoor tanning
   - immunocompromised
3. ) Classification
   - superficial spreading: most common
   - nodular: grows vertically, most aggressive
   - lentigo maligna: in sun-damaged sites
   - acral lentiginous: on soles of feet, palms, and nails
4. ) ABCDE Signs - for superficial MM
   - Asymmetry of shape and colour
   - Border irregularity inc smudgy or ill-defined margin
   - Colour variation and change
   - Diameter >6mm
   - Evolving (enlarging, changing)
   - common differential is seborrhoeic keratosis: won’t have any of these signs
5. ) Management - 2WW referral where they will:
   - inspect the lesion with a dermatoscope
   - excisional biopsy if MM is suspected: stage 3/4 will require adjuvant immuno/chemotherapy
   - Breslow thickness determines the depth and is the most important prognosis factor
   - Clark’s level: layers the melanoma has penetrated, also another prognostic indicator

Question 2

Seborrhoeic Keratosis

Pathophysiology
Clinical Features
Management
Solar Lentigo

Answer 2

1. ) Pathophysiology - benign slow overgrowth of epidermal keratinocytes, unknown aetiology
   - very common in older adults
2. ) Clinical Features
   - well-defined ‘stuck on’ warty (verrucous) plaque with a fissured keratin surface
   - multiple lesions often present and can occur anywhere except the palms, soles, mucous membranes
   - often asymptomatic, can be itchy, can come off
3. ) Management - nothing unless symptomatic:
   - cryotherapy, curettage, or laser ablation
4. ) Solar Lentigo - variant of seborrhoeic keratosis
   - benign, well defined patch of hyperpigmented skin
   - very common especially in older adults

Question 3

Weighted 7-point Checklist for Pigmented Lesions

Scoring
Major Features
Minor Features

Answer 3

1. ) Scoring - separate major and minor features
   - major scores 2 points each, minor scores 1 point
   - refer for a 2WW if a patient score 3 or more
2. ) Major Features - change in size, irregular shape or border, irregular colour
3. ) Minor Features - >7mm diameter, inflammation, oozing or crusting, change in sensation (inc itch)

Question 4

Squamous Cell Carcinoma

Pathophysiology
Risk Factors
Clinical Features
Management

Answer 4

1. ) Pathophysiology - invasive growth of keratinocytes from the epidermis into the dermis
   - in non-invasive SCC, keratinocytes stay in the epidermis e.g. actinic keratosis (partial thickness) and Bowen’s disease (full thickness)
   - can metastasise but high survival rate (99%-5y)
2. ) Risk Factors
   - ↑age, male, smoking, PH/FH of skin cancer
   - UV exposure: occupation, tanning beds, psoralen + UVA therapy (PUVA)
   - has many moles, previous h/o of getting sunburnt
   - pale skin, light eyes/hair, immunosuppression (especially renal transplant patients)
   - non-invasive SCC: actinic keratosis, Bowen’s disease
3. ) Clinical Features
   - irregular, ill-defined, scaly, ulcerated red nodule
   - indurated: feel a firm lump underneath the skin
   - rapid evolution (enlarging), tender, bleeding
   - sun-exposed sites: face, ears, arms, hands, shins
   - varying sizes (mm-cm), grow over weeks to months
4. ) Management - 2WW referral
   - surgical excision, radiotherapy (can’t have surgery)
   - cryotherapy
   - advice on sun protection

Question 5

Actinic (Solar) Keratosis

Pathophysiology
Clinical Features
Management

Answer 5

1. ) Pathophysiology - premalignant skin condition which can precede the development of a SCC
   - risk factors: fair skin, h/o of sunburn, sunlight exposure, immunocompromised
2. ) Clinical Features
   - thickened papules or plaques with surrounding erythematous skin and a keratotic, rough, warty surface
   - can be tender or asymptomatic
   - sun-exposed sites: scalp, face, backs of hands
3. ) Management - managed to prevent SCC
   - diagnosed clinically or via dermatoscopy
   - cryotherapy 1°, topical agents 2°: diclofenac, efudix (5-fluorouracil), Imiquimod (modifies immune response)
   - cutterage or surgical excision last line

Question 6

Basal Cell Carcinoma (BCC)

Pathophysiology
Risk Factors
Clinical Features
Management

Answer 6

1. ) Pathophysiology - locally invasive tumour of keratinocytes due to UV exposure –> DNA mutation
   - most common skin cancer, but rarely metastasises
   - types: nodular (most common), superficial, pigmented, cystic, keratotic, morphoeic
2. ) Risk Factors
   - ↑age, male, PH/FH of skin cancer, immunosuppressed
   - fair skin, h/o of previous/frequent sun burn
   - UV exposure: outdoor occupation, tanning beds
3. ) Clinical Features
   - small, skin-coloured nodule +/- central depression
   - pearly rolled edge and surface telangiectasia
   - rodent ulcer: can become necrotic or ulcerated
   - sun-exposed sites: especially the head and neck
4. ) Management
   - routine referral unless there is concern that a delay may have a significant impact, due to site or size
   - surgical excisional biopsy with a 4mm margin
   - Mohs microscopically controlled surgery for recurrent, ill-defined and large tumours of the face
   - curettage and cautery
   - topical: Imiquimod or 5-Fluorouracil
   - cryotherapy, photodynamic therapy, radiotherapy