Skin Malignancy Flashcards
(27 cards)
Malignant Melanoma
Most common cancer of young adults aged between 20-39 years and more common in women.
The presence of naevi is the most common predictor of risk of malignant melanoma.
Diagnosis – ABCDE – asymmetry, border irregular, colour non-uniform, diameter >7mm and elevation.
MM - 4 Types
- Superficial spreading melanoma – 70% most common type – often found on the legs of young women and trunk of middle aged men. Red, white and blue in colour with an irregular edge.
- Nodular melanoma – 15-30% second most common type – often occurs on the trunk, polypoid in shape, raised, smooth surface, irregular edge and frequently becomes ulcerated.
- Lentigo maligna melanoma – arises in a lentigo maligna (a melanotic freckle) that often occurs on the face or dorsum of the hands and forearm. The underlying lesion is flat and brown to black in colour with an irregular outline. Malignant area is thicker and darker in colour.
- Acral lentiginous melanoma – least common and occurs on hairless skin e.g. palms and soles and more common in oriental and Black races. There is irregular brown/black pigmentation.
MM - Differential
- Malignant – pigmented basal cell carcinoma.
- Benign – pigmented naevus (moles – increased number of melanocytes producing too much melanin), freckles (normal number of melanocytes producing too much melanin), lentigo (increased number of melanocytes producing normal amounts of melanin), pigmented seborrhoeic keratosis, dermatofibromas or thrombosed haemoangiomas.
MM - Predisposing Factors
- Congenital – xeroderma pigmentosum (a familial condition associated with failure of DNA transcription leading to defective DNA repair), dysplastic naevus syndrome (risk of malignant melanoma is 100% if 2 family members affected), large congenital naevi or family history.
- Acquired – sunlight exposure, >20 benign pigmented naevi or previous melanoma.
MM - Staging
Breslow Thickness - gives 10 year Survival (%):
- <0.76mm = 92%
- <3mm = 50%
- <4mm = 30%
- Lymph node involvement = <40%
MM - Management
- Main lesion – <0.76mm – excise with a 1cm margin, 0.76-1mm – excise with a 2cm margin and >1mm - excise with a 3cm margin of grossly normal tissue down to the deep fascia.
- Nodal spread – if clinical suspicions of nodal metastasis take a biopsy or fine needle aspiration.
MM - Prevention and Prognosis
- Prevention – avoidance of causative factors e.g. public health campaigns to reduce sun exposure.
- Poor prognostic indicators – increasing age, male, lesion on the trunk (especially the back), scalp, hand and foot, ulceration of the tumour, depigmentation and amelanotic melanomas.
Squamous Cell Carcinoma
- May occur on any part of the face (usually in sun exposed areas where skin looks weathered), appears vascular, has a raised and everted edge, may be of considerable size (>1cm), there may be erosion of the facial architecture if the tumour is advanced and it may have an area of central ulceration.
- Palpate regional lymph nodes – however only 5% have metastasised by the time they present to you.
SCC - Differential
- Malignant – basal cell carcinoma or malignant melanoma (amelanotic).
- Benign – solar keratosis, infected seborrhoeic wart, pyogenic granuloma.
SCC - Predisposing factors
- Congenital – xeroderma pigmentosum
- Acquired – environmental agents – sunlight or ionising radiation, pre-existing skin lesions – solar keratosis or Bowen’s disease, infections – viral warts, immunosuppression – antirejection post-transplant or in HIV infection or in chronic venous ulceration = Marjolin’s ulcer.
SCC - Management
- Primary lesion – excision with a 1cm margin or radiotherapy for un-resectable lesions.
- Nodal spread – surgical block dissection if palpable nodes or Marjolin’s ulcer or radiotherapy.
Basal Cell Carcinoma
- Occurs on hair bearing sun exposed skin of the elderly, especially around the eye. Can be divided into:
- Raised – can be nodular – the most common type with a well-defined rolled, pearly edge and a central area of ulceration or cystic – there is a large cystic nodule.
- Not raised – can be pigmented and confused with malignant melanoma, sclerosing with ill-defined edges and may be ulcerated, cicatrical with multiple superficial erythematous lesions inter-dispersed with pale atrophic lesions or superficial with erythematous scaly patches.
BCC - Differential
- Benign – keratocanthoma.
- Malignant – squamous cell carcinoma.
BCC - Predisposing factors
- Congenital – xeroderma pigmentosum.
- Acquired – sunlight, carcinogens e.g. cigarette smoke or previous radiotherapy.
BCC - Management
Raised tumours can be excised with a 0.5cm margin but tumours that are not raised should have a wider margin of excision – particularly around the eyes and the nose.
Eczema - Classification
- Endogenous – atopic, discoid, hand, seborrhoeic, venous (gravitational) and asteatotic eczema
- Exogenous – contact (either irritant or allergic), photosensitive eczema or lichen simplex.
Atopic Eczema - Clinical Features
Itchy erythematous scaly patches especially in flexures around the neck, elbows, knees and ankles (but in infants can start on the face).
Very acute lesions may weep or exude and can show small vesicles and rubbing can produce skin thickening with exaggerated skin markings.
In pigmented skin there can be extensor involvement and hyper or hypopigmentation following inflammation.
Atopic Eczema - Complications
Retarded growth, broken skin commonly becomes secondarily infected by bacteria (often staph aureus or pseudomonas), cutaneous viral infections such as viral warts or molluscum (spread by scratching), HSV can cause eczema herpeticum (can be fatal and requires rapid treatment with acyclovir), ocular complications include conjunctival irritation, keratoconjunctivitis and cataracts.
Atopic Eczema - Diagnosis
Normally diagnosed clinically or with a RAST test (radio-immunoabsorbent assay) of blood or indirectly by skin prick testing to test for high specific IgE levels to ingested or inhaled antigens.
Atopic Eczema - Management
- General measures – avoid precipitants, wearing cotton clothes, not getting too hot or changes in diet.
- Emollients - form a protective barrier and reduce water loss from the skin. Come in creams, soap substitutes and bath oils.
- Topical steroids – the face and young children should only be treated with mild or moderate strength steroids - 1% hydrocortisone. More potent steroids should only be used for 7-10 days.
- Topical immunomodulators – tacrolimus ointment does not cause skin atrophy and can be used on sensitive areas such as the face and eyelids.
- Anti-histamines - can be given to reduce pruritis e.g. cetirizine.
- Antibiotics – flucloxacillin or erythromycin should be given for 7-10 days for secondary infection.
- Systemic steroids - in severe cases.
Discoid Eczema
A morphological variant of eczema characterised by well demarcated scaly patches, especially on the limbs so can often be confused with psoriasis. More common in adults and can occur in both atopic and non-atopic individuals.
Seborrhoeic Eczema
- Aetiology –overgrowth of Pityrosporum ovale with a strong immune response to this yeast produces scaling and inflammation.
- Childhood – usually presents as a cradle cap in first few months of life.
- Young adults – usually presents as erythematous scaling along the sides of the nose, in the eyebrows, around the eyes and extending into the scalp (which shows marked dandruff).
- Elderly – more severe and often involves large areas of the body and can cause erythroderma.
- Treatment – a combination of a mild steroid ointment and a topical antifungal cream will stop eruptions.
Psoriasis
A common disorder affecting 2% of the population characterised by well demarcated red scaly plaques.
The skin becomes inflamed and hyperproliferates at about 10 times the normal rate. Age of onset occurs in 2 peaks – early onset between 16-22 years is more common and late onset between 55-60 years.
Psoriasis - Aetiology
Polygenic (73% concordance in MZ and 20% in DZ) with certain environmental triggers such infection (group A streptococcus), drugs (lithium), ultraviolet light, alcohol abuse and possibly stress.
