Pathology of non-pigmented lesions

Question 1

Give an example of benign, premalignant and malignant skin tumours

Answer 1

Benign - seborrheic keratosis
Premalignant - actinic keratosis & bowens & viral lesions
Malignant - SSC & BCC

Question 2

What is a seborrheic keratosis?

Answer 2

Benign proliferation of epidermal keratinocytes

Question 3

What age group typically presents with seborrheic keratoses? Where do they typically present?

Answer 3

Elderly. Face & trunk

Question 4

What do seborrheic keratosis look like?

Answer 4

Stuck on appearance with a greasy hyperkeratotic appearance

Question 5

Name a specific type of seborrheic keratosis? What is the typical histological appearance of a seborrheic keratosis?

Answer 5

Horn cyst. Epithelial acanthosis and hyperkeratosis

Question 6

What is the Leser-Trelat sign?

Answer 6

An eruption of seorrheic keratosis is usually a paraneoplastic symptom of internal malignancy

Question 7

What are the three main types of basal cell carcinoma?

Answer 7

Superficial, nodular and infiltrative (morphoeic)

Question 8

Peripheral palisading is typical histological feature of what?

Answer 8

BCC

Question 9

How does BCC kill?

Answer 9

Very rarely will invade the eye and then brain. (OR if left many, many years it may cause problems)

Question 10

How often does BCC metastasise?

Answer 10

Almost never

Question 11

Why might resection of BCC be challenging?

Answer 11

BCCs often have poorly defined margins and may spread along nerves

Question 12

What are the precursors to SSC and where are they commonly found?

Answer 12

Actinic keratosis - face and scalp
Bowen’s - legs
Viral lesions - anogenital area

Question 13

How does bowen’s disease present?

Answer 13

scaly (often erythematous) patch/plaque with an irregular border

Question 14

What does Bowen’s disease often co-exist with?

Answer 14

Venous stasis

Question 15

What are severely atypical actinic keratosis called?

Answer 15

Bowenoid

Question 16

What is erythroplasia of Queryat?

Answer 16

Penile bowen’s

Question 17

HPV is associated with anogenital dysplasia. T/F

Answer 17

True (type 16)

Question 18

Where may SSC occasionally arise?

Answer 18

Chronic ulcers, burn sites, sinuses, chronic lupus vulgaris

Question 19

What are some rare associations with SSC?

Answer 19

Xeroderma pigmentosum, epidermolysis bullosa

Question 20

What is the prognosis of SSC?

Answer 20

Generally good - locally invasive and low (but definite) risk of metastases

Question 21

What are the adverse prognostic features of SSC?

Answer 21

Thickness>4mm, poor differentiation, lymph/vascular invasion, perineural spread, specific sites (nose, ear, scalp)

Question 22

What is dermatofibrosacroma protuberans?

Answer 22

Extremely rare tumour arising from the dermis and prone to metastases