Skin pathology

Question 1

Features of the epidermis?

Answer 1

Stratified squamous epithelium
Melanocytes
Keratin
Langerhan’s cells (APC)

Question 2

Features of the dermis?

Answer 2

Fibrous and adipose connective tissue 
Nerves 
Blood vessels 
Lymphatics 
Smooth muscles (arrector pili) 
Skin appendages (hair follicles, sebaceous glands, sweat glands, etc)
Inflammatory cells

Question 3

General epidemiology of skin cancers?

Answer 3

NMSC’s are much more common, but melanomas are much more likely to cause death.

Question 4

Histological and gross features of BCCs?

Answer 4

Small dark blue palisading cells

Risk of local invasion and destruction (causing a Rodent ulcer appearance)

Papular lesion with pearly surface.

Question 5

What are dysplastic squamous epidermal lesions and give examples?

Answer 5

Precursors of SCC. However low risk of progressing to SCC.

1. Actinic (solar) keratosis= Dysplastic epidermis at sun-exposed sites.
2. Bowen’s disease= Severe/full-thickness dysplasia of epidermis at sun exposed sites. (in-situ SCC).

Question 6

Physical appearance of dysplastic squamous epidermal lesions?

Answer 6

Multiple reddened crusty spots. AK may be associated with a cutaneous horn.

Question 7

True or False?: All melanoma lesions are pigmented and all NMSC are non-pigmented.

Answer 7

False

Skin lesions (melanoma or NMSC) can be pigmented or non-pigmented. Therefore, all lesions/bumps/lumps/moles should be sent to pathology to rule out or in melanoma.