Non-Melanoma Skin Cancers

Question 1

What is an actinic keratosis?

Answer 1

Ill, defined, scaly, erythematous papules or plaques on a background of sun-damaged skin.

Question 2

How do actinic keratoses feel?

Answer 2

Sandpaper like, gritty sensation felt on palpation.

Question 3

Where are actinic keratoses found?

Answer 3

Sites of sun exposure (face, ears, scalp if bald, neck, limbs)

Question 4

Pathophysiology of actinic keratoses?

Answer 4

UV radiation damage to keratinocytes from repeated sun exposure (esp UVB).

Question 5

What is the risk of actinic keratoses?

Answer 5

May transform into SCC (~1/1000); higher if AK persistent.

Question 6

Ddx of actinic keratosis?

Answer 6

• SCC in situ
• Superficial BCC
• Seborrheic keratosis
• Cutaneous lupus erythematosus

Question 7

Ix of actinic keratoses?

Answer 7

Biopsy lesions refractory to treatment.

Question 8

Management of actinic keratoses?

Answer 8

• Destructive: cryotherapy, electrodessication and curettage
• Pharm: 5-fluorouracil cream for 2-3/52, imiquimod cream 8-10/52.
• Excision

Question 9

What is leukoplakia?

Answer 9

Morphologic term describing homogeneous or speckled white plaques with sharply demarcated borders.

Question 10

Sites of leukoplakia?

Answer 10

Oropharynx, floor of mouth, soft palate, tongue.

Question 11

Pathophysiology of leukoplakia?

Answer 11

Premalignant condition; strongly associated with tobacco use and alcohol consumption.

Question 12

Ix in leukoplakia?

Answer 12

Bx essential as premalignant.

Question 13

Mx leukoplakia?

Answer 13

• Eliminate carcinogenic habits
• Excision
• Cryotherapy

Question 14

What are the subtypes of BCC?

Answer 14

• Noduloulcerative (typical)
• Pigmented variant
• Superficial variant
• Sclerosing variant

Question 15

Describe the features of noduloulcerative (typical) BCC.

Answer 15

Skin coloured papule / nodule with rolled, translucent (“pearly”) telangiectatic border and depressed / eroded / ulcerated centre.

Question 16

Describe the pigmented variant of BCC.

Answer 16

Flecks of pigment in translucent lesion with surface telangiectasia. May mimic malignant melanoma.

Question 17

Describe the features of superficial variant of BCC.

Answer 17

Flat, tan to red-brown plaque. Often with scaly, pearly border and fine telangiectasia at margin. Least aggressive subtype.

Question 18

Describe the features of the sclerosing (morpheaform) variant of BCC?

Answer 18

Flesh / yellowish-coloured, shiny papule/plaque with indistinct borders, indurated.

Question 19

Pathophysiology of BCC?

Answer 19

Malignant proliferation of basal keratinocytes of the epidermis. Usually due to UVB exposure; may also occur in previous scars, trauma, radiation, arsenic exposure.

Question 20

What is genetic predisposition to BCCs?

Answer 20

Gorlin syndrome

Question 21

BCC malignant potential?

Answer 21

Low grade cutaneous malignancy; locally aggressive, rarely metastatic.

Question 22

Epidemiology of BCC?

Answer 22

• Most common human malignancy (75% malignant skin tumours)
• M>F, >40yr
• Chronic sun exposure

Question 23

DDx BCC?

Answer 23

Benign: sebaceous hyperplasia, intradermal melanocytic naevus, dermatofibroma
Malignant: nodular malignant melanoma, SCC.

Question 24

Mx BCC?

Answer 24

• Shave excision and electrodessication and curettage for most BCCs.
• Life long follow up

Question 25

Prognosis BCC?

Answer 25

95% cure rate if lesion

Question 26

Clinical presentation of SCC?

Answer 26

• Indurated erythematous nodule/plaque with surface scale / crust +/- ulceration.
• Enlarges faster than BCC

Question 27

Sites of SCC?

Answer 27

Face, ears, scalp, forearms, dorsum of hands.

Question 28

Pathophysiology of SCC?

Answer 28

-Malignant neoplasm of keratinocytes (primarily vertical growth).

Question 29

RFx SCC?

Answer 29

• UV radiation, PUVA, ionising radiation therapy/exposure, chemical carcinogens, HPV
• may occur in old scar

Question 30

SCC epidemiology?

Answer 30

Primarily sun exposed skin i elderly, M>F.

Question 31

DDx SCC?

Answer 31

• Benign: nummular eczema, psoriasis, irritated seborrheic keratosis.
• Malignant: keratoacanthoma, Bowen’s disease, BCC.

Question 32

Mx SCC?

Answer 32

• Excision w/ primary closure, flaps or grafting

- Lifelong r/v

Question 33

Prognosis in SCC?

Answer 33

75% over 5y; 5-10% metastasize.

Question 34

SCC good prognostic factors?

Answer 34

Early treatment, negative margins, small size of lesion.

Question 35

What is Bowen’s disease?

Answer 35

Squamous cell carcinoma in situ.

Question 36

Clinical presentation of Bowen’s disease?

Answer 36

Erythematous plaque w/ sharply demarcated red and scaly border. Often 1-3cm in diameter on skin and mucous membranes.

Question 37

Bowen’s disease malignant potential?

Answer 37

Evolves to SCC in 10-20% cutaneous lesions and >20% mucosal lesions.

Question 38

Mx Bowen’s disease?

Answer 38

• Biopsy for dx
• Cryosurgery
• Shave excision with electrodessication and curettage

Question 39

Clinical presentation keratoacanthoma?

Answer 39

Rapidly growing, firm, dome-shaped erythematous or skin coloured nodule with central keratin filled crater resembling an erupting volcano. May spontaneously regress, leaving a scar.

Question 40

Pathophysiology of keratoacanthoma?

Answer 40

Epithelial neoplasm with atypical keratinocytes in epidermis. Low grade SCC variant.

Question 41

Aetiology of keratoacanthoma?

Answer 41

HPV, UV radiation, chemical carcinogens (tar, mineral oil).

Question 42

Epidemiology of keratoacanthoma?

Answer 42

> 50y rare;

Question 43

DDx keratoacanthoma?

Answer 43

Treat as SCC until proven otherwise.

-Hypertrophic solar keratosis, verruca vulgaris.

Question 44

mx keratoacanthoma?

Answer 44

Surgical excision; treat similarly to SCC.