Treatment of malignant tumours

Question 1

What are the two types of biopsy and describe them

Answer 1

Incisional vs excisional

Incisional - portion of the lesion is removed with a blade or punch biopsy and sent for histology

Excisional - entire lesion is removed and then sent to histology for diagnosis.

Types of excisional biopsy -

• Shave; using a blade to remove shallow epithelial tumours such as seborrhaeic keratosis or papilloma
• Full-thickness skin excision; for tumours not confined to the epidermis

Question 2

What are the aims of surgical excision

Answer 2

To remove the entire tumour whilst preserving as much normal tissue as possible

Question 3

What kind of surgical excision can be done with small tumours

Answer 3

For small tumours excisional biopsy is sufficient and the defect can be closed directly, and await histological confirmation of margin clearance

Question 4

What kind of surgical excision can be done with small BCCs

Answer 4

For small BCCs excision of the entire lesion along with 2-4mm margin of normal skin is usually enough

Question 5

What kind of surgical excision is required with more aggressive tumours?

Answer 5

For more aggressive tumours more radical excision is required e.g. SCC, SGC, Melanoma. Reconstruction can only take place once histology confirms margin clearance. This can be sped up by paraffin embedded specimens but reconstruction still needs to take place on a different day

Question 6

How can reconstruction surgery take place on the same day?

Answer 6

The use of frozen sections of Moh’s micrographic surgery

Question 7

What is involved in standard frozen sections

Answer 7

Involves histological examination of the margins of the excised specimen at the time of surgery to ensure they are tumour free. If no tumour cells are detected the eyelid is reconstructed. If tumour cells are detected further excision takes place until the specimen is tumour free

Question 8

What is Mohs micrographic surgery

Answer 8

This involves layered excision of the tumour. Specimens around the eye are usually frozen as the fixing paste used when it was first described can cause ocular irritation.

Processing of each layer enables a map of the tumour edges to be developed. Further tissue is taken in any area where the tumour is still present until clearance is achieved.

Although time consuming it maximises the chances of total tumour excision whilst minimising sacrifice of normal tissue.