Dysplastic/Pre-malignant Skin Lesions Flashcards
Skin Cancer (29 cards)
Define Dysplastic/Pre-malignant Skin Lesions
(1) Precursors to SCC (squamous cell carcinoma)
(2) Only need to remove if become malignant
(3) Precursors show dysplasia
= abnormal cell growth
What are the pre-malignant skin lesions names?
- Actinic (solar) keratoses
- Bowen’s disease
(intraepithelial carcinoma) - Keratoacanthoma
What is the histological hallmark of actinic keratosis?
Partial thickness dysplasia of epidermal keratinocytes
What percentage of actinic keratoses progress to SCC?
Less than 1%
What are the clinical features of actinic keratosis?
(1) Scaly
(2) Erythematous papules or patches
(3) With a gritty/rough texture on sun-exposed areas
(4) such as -scalp, face, hands
What are the main treatment options for actinic keratosis?
- Lesion-based
= Cryotherapy, curettage and cautery - Field-based
= Topical 5-FU, imiquimod, photodynamic therapy
What is Bowen’s disease?
Squamous cell carcinoma in situ
= abnormal keratinocyte growth confined to the epidermis without invading the basement membrane
meaning it is an early form of skin cancer where abnormal cells are present in the epidermis only and have not invaded deeper layers (dermis)
Define “In situ”
The cancerous cells are confined to their original location and have not spread beyond the epidermis
What does basement membrane mean?
The layer that separates the epidermis from the deeper skin layers
What is the key histological feature of Bowen’s disease?
(1) Full-thickness dysplasia of epidermal keratinocytes
(2) Confined to the epidermis
What is a common site of Bowen’s disease in fair-skinned women?
Lower legs
What are the clinical features of Bowen’s disease?
(1) Slowly enlarging
(2) Well-demarcated
(3) Scaly red patch/plaque
(4) With an irregular border
(5) no dermal invasion
What viral infection is associated with genital Bowen’s disease?
HPV-16 & HPV-18
How is Bowen’s disease managed?
✅ Cryotherapy
= freezing with liquid nitrogen
✅ 5-Fluorouracil (5-FU) cream
= destroys abnormal cells
✅ Imiquimod
= stimulates immune response
✅ Photodynamic therapy
= light treatment after applying a photosensitising agent)
How does Bowen’s disease typically present in MCQs?
(1) Red
(2) Scaly keratinocyte dysplasia
(3) Often on an old lady’s lower legs
Define Keratoacanthoma
Rapidly growing epidermal tumours
What is the clinical hallmark of keratoacanthoma?
(1) Rapidly growing
(2) Red papule
(3) With a central keratinous plug
(4) Often on sun-exposed skin
How long does a keratoacanthoma take to regress spontaneously?
~3 months, leaving a pitted scar
Why are keratoacanthomas usually excised?
Difficult to distinguish from SCC clinically
How large can keratoacanthomas typically grow?
2–3 cm in diameter
What is the risk of actinic keratosis developing to malignancy if left untreated?
20%
What is the cause of actinic keratosis?
Exposure to solar radiation causes mutation of the p53 tumour suppressor gene
Key features of actinic keratosis include what?
(1) Red, pink or flesh coloured scaly plaques or patches
(2) Occurs on sun-exposed skin
(eg - face, ears, scalp, neck, backs of hands)
(3) Sometimes, the surface can be keratotic (dry and rough)
(4) Tender or itchy at times
(5) Can be flat or slightly raised
(6) Rough texture, feeling like sandpaper when touched
(7) Sometimes appear white when they are more superficial or have thickened keratin
An 82-year-old man presents to the GP, worried about a lesion on his head. He says it has been there for quite some time, but his wife is very worried about it. He tells you that it is not tender but can sometimes be itchy. On examination, the patient has a 5 mm, white, scaly plaque on the top of his head. Another similar lesion around the back of his head is also noted. The surrounding skin on his head has some hyperpigmentation and there are some very pale patches.
Given the history and examination, what is the most likely diagnosis?
Actinic keratosis
