sebaceous cysts

Question 1

definition of sebaceous cysts

Answer 1

epithelium lined, keratinous, debris filled cyst arising from a blocked hair follicle

more correctly known as epidermal cyst

Question 2

aetiology of a sebaceous cyst

Answer 2

occlusion of the pilosebaceous gland

traumatic insertion of epidermal elements into the dermis and embryonic remnants

Question 3

RF for sebaceous cysts

Answer 3

more frequent in Gardener’s syndrome

Question 4

epidimology of sebaceous cysts

Answer 4

extremely common

any age

Question 5

Sx of sebaceous cyst

Answer 5

nontender slow-growing skin lesion, often multiple

common on hair-bearing areas of the body, especially face, scalp, trunk or scrotum

may become red, hot, tender if superimposed inflammation or infection

firm, round, mobile SC nodules of varying size

Question 6

signs of sebaceous cyst

Answer 6

smooth tethered lump with overlying central skin punctum

may express granular creamy material with an unpleasant smell

infection common and foul pus exits through the punctum

Question 7

pathology of sebaceous cysts

Answer 7

not from sebaceous glands

from cystic proliferation of epidermal cells within the dermis

source of the dermis is the infundibulum of the hair follicle

inflammation is usually a foreign body, granulomatous reaction to materal contained within cysts

contain keratin not sebum

Question 8

Ix of sebaceous cysts

Answer 8

none usually required

skin biopsy or FNA may be needed to rule out other dx

Question 9

complications of sebaceous cyst

Answer 9

rupture into dermis -> swelling, red, tender
due to trauma / infection (satph aureus)
recurrance
surgery -> bleeding, secondary infection, scarring
SCC rarely

Question 10

mx of sebaceous cyst

Answer 10

reassurance

surgical excision with intact capsule

infection -abx, incision and drainage

occasionally resolve spontaneosly