Derm - Skin Cancers

Question 1

name the 3 main types of skin cancer and the cell type they arise from. which is most common?

Answer 1

1. basal cell carcinoma (most common) - arise from hair follicles
2. squamous cell carcinoma - arise from keratinising cells of epidermis
3. malignant melanoma - arise from melanocytes (in stratum basale of epidermis)

Question 2

describe the common appearance of a basal cell carcinoma

Answer 2

• usually in sun-exposed areas of head and neck
• early lesions often small, translucent or pearly, and have raised areas with telangiectasia
• indurated edge and ulcerated centre

Question 3

describe the common appearance of a squamous cell carcinoma

Answer 3

• often in sun-exposed areas
• indurated nodular keratinising or crusted tumour, with hard, raised edges
• may ulcerate

Question 4

which features of a lesion should prompt 2ww pathway referral for melanoma?

Answer 4

Suspicious pigmented lesion with score of 3+.

Weighted 7-point checklist:

• Major features of lesion (2 pts each)
  
  • change in size
  • irregular shape
  • irregular colour
• Minor features of lesion (1 pt each)
  
  • largest diameter 7mm+
  • inflammation
  • oozing
  • change in sensation

Question 5

what is the difference between melanoma in situ and invasive melanoma?

Answer 5

Melanoma in site = confined to epidermis

Invasive melanoma = grows through dermis. Can spread to other tissues via lymphatic system to local LNs or via bloodstream to other organs (e.g. liver, lung, bone and brain).