Condition- Sebaceous Cysts

Question 1

List the two types of sebaceous cysts and state which structure they arise from

Answer 1

1. Epidermoid cysts: originate in the epidermis
2. Pilar cysts: originate from hair follicles

Note: they contain Keratin NOT sebum

Question 2

What causes the development of sebaceous cysts?

Answer 2

• Occlusion of the pilosebaceous gland
• Can be caused by traumatic insertion of epidermal elements into the dermis
• Embryological remnants

Question 3

Name a hereditary condition which may lead to the development of sebaceous cysts + State it’s pattern of inheritance

Answer 3

Gardner’s Syndrome = autosomal dominant condition characterised by the presence of multiple polyps in the colon and in extra-colonic sites (e.g. sebaceous cyst, thyroid cancer, fibroma)

Question 4

Which age group often suffers from epidermoid cysts?

Answer 4

Young and middle aged adults- common in acne

Question 5

Which parts of the body are sebaceous cysts often found?

Answer 5

Common on hair-bearing regions of the body (e.g. face, scalp, trunk or scrotum)

Question 6

Describe the appearance and characteristics of sebacous cysts

Answer 6

• Non-tender slow-growing skin swelling
• May become red, hot and tender if there is superimposed infection or inflammation
  
  • Infection is quite common
  • These will discharge cheesy foul-smelling pus
• Firm, round, mobile intradermal/ SC nodules of varying size
• CENTRAL PUNCTUM

Question 7

How would you investigate a pt presenting with a lump which is suspected to be a sebaceous cyst?

Answer 7

• Clinical examination- usually no further investigation needed
• Skin biopsy/ FSA to rule out differentials