Squamous Cell Carcinoma

Question 1

What is SCC?

Answer 1

• A locally invasive malignant tumour of the keratinocytes arising from the epidermal layer

Question 2

What are the causes of SCC?

Answer 2

• Excessive UV exposure - Primarily UVB
• Pre- Malignant skin conditions ( Actinic Keratoses + Bowen’s Disease )
• Chronic Inflammation
• Immunosuppression - Following renal transplant, HIV
• Genetic Predisposition
• Smoking
• Herpes Simplex or HPV

Question 3

What are the Clinical Features of SCC?

Answer 3

• Located on Sun exposed areas
• Grow over weeks to months
• Can be nodular, indurated or keratinised
• Associated with bleeding and ulceration

Question 4

What are the Differential Diagnoses for SCC?

Answer 4

• Bowen’s Disease
• Actinic Keratosis
• Keratoacanthoma
• Verrucous Carcinoma
• Cutaneous Horns

Question 5

What Investigations would you do?

Answer 5

• History and Examination
• Palpation of Regional Lymph Nodes
• Dermoscopy - White circles/ Structureless areas, looped blood vessels and a central keratin plug

Question 6

What is the mainstay Surgical treatment for SCC?

Answer 6

• Surgical Excision ( Treatment of Choice) - excision biopsy with peripheral margins
• Moh’s Micrographic Surgery - necessary for ill-defined, large, recurrent tumours

Question 7

What are the margins for low risk SCC?

Answer 7

• 4mm

Question 8

What are the margins for high risk SCC?

Answer 8

• 6mm

Question 9

What are the margins for very high risk SCC?

Answer 9

• 10mm

Question 10

When would dermatologists perform curettage and cautery?

Answer 10

• For immunocompetent patients who have small <1cm and clinically low risk SCC

Question 11

What are the non- Surgical managment options?

Answer 11

-1. Primary Radiotherapy (surgery is not feasible)
- Adjuvant radiotherapy ( close or involved margins if further surgery is not possible)
- 2. Immune Checkpoint Inhibitors - locally advanced SCC
-3. Chemotherapy - 3rd line for people not suitable for Immune Checkpoint inhibitors, generally more poorly tolerated

Question 12

What is the Classification system for SCC?

Answer 12

• Broder’s Grading System (1-4)

Question 13

What are the types of Biopsy?

Answer 13

• Excisional Biopsy
• Incisional Biopsy
• Punch Biopsy

Question 14

What is an Excisional Biopsy?

Answer 14

• The whole lesion is excised with the margin of normal tissue
• Removes all abnormal tissue
• Requires more time and results in a larger scar

Question 15

What is an Incisional Biopsy?

Answer 15

• A portion of the lesion is removed via a relatively smaller skin incision
• Quicker Procedure and less invasive
• Lesion will require further treatment

Question 16

What is a Punch Biopsy?

Answer 16

• A small Deep hole is punched out of the lesion
• Quicker procedure, Full thickness sample, good cosmetic outcome
• Lesion will require further treatment