Skin biopsy techniques Flashcards
Scars on the chest often stretch.
F Scars on back.
The ventral forearm has a tendency to heal well after biopsy.
F
The dorsum of the hand has a tendency to heal well after biopsy.
T
There is a theoretical risk of interaction of local anaesthetic and adrenaline with MAO inhibitors, beta blockers and TCAs
T
Crust should be gently removed by irrigation prior to biopsy.
T
20% neutral buffered formalin is the usual fixative used for biopsies.
F 10%
Colonisation with S.aureus is more common in patients with psoriasis, atopic dermatitis, diabetes, IVDUs, or those taking isotretinoin
T
Sterile gloves have a 0.15-0.3% failure rate.
F 1.5-3%. Increases to 66% after 15 mins.
There is a 30% incidence of unnoticed punctures during procedures.
T
Skin tags can be pulled away from the surface and snipped at the base
T
Infection is less likely from a shave or curette biopsy compared to a punch or incisional approach.
T
Antibiotics should be considered for all procedures below the knee, wedge excision of the lip and ear, and lesions in the groin.
T
In order to be effective and truly prophylactic, antibiotics should be administered 30 mins before a procedure.
T
There is good evidence to support the use of prophylactic topical antibiotics.
F
It is best to pull polypoid lesions very firmly prior to performing a snip excision.
F Firmer pulling results in a wider cut, including non-involved skin at the base.
Shave biopsy is not suitable if trying to distinguish between a KA-type SCC and an invasive SCC.
T
When dealing with popular nevi, the plane of removal should be just above the surrounding skin so that natural shrinkage takes the level of the central potion down to level of surrounding skin
T
With a punch biopsy, stretching the skin at right angles to relaxed skin tension lines will change the defect from a circular to oval shape and minimize a dog-ear formation and aid linear closure
T
With a scalp biopsy, it is important to make the plane of the biopsy parallel to the direction of the hair shafts as they leave the scalp.
T
With genital biopsy on the glans it is bed to take an ellipse
F No – this has a tendency to create a ragged edge; better to take a shave biopsy or make 2 parallel incisions
