Introduction
If your dermatologist cannot rule out the possibility of skin cancer,
a biopsy will be performed in order to make a diagnosis. This involves
removing part or all of the suspicious mole for examination by a pathologist.
You will be given a local anesthetic so the procedure is nearly painless.
There are three types of biopsies performed for diagnosis of skin cancer.
One of these, the shave biopsy, should not be used if melanoma is suspected.
The Excisional
Biopsy
In an excision biopsy, the entire suspect area is removed. A local anesthetic
is injected. Then the entire lump, spot, or sore is removed, going as
deep as necessary to get the entire area. The incision is then closed
with stitches. Bleeding is controlled by pressure. If a large area is
biopsied, a skin graft may be used to cover it. [Ref]
The Punch
Biopsy
A punch biopsy is also sometimes used by a dermatologist to collect
a tissue sample from a suspected mole. After a local anesthetic is injected,
a biopsy punch, which is basically a small (3 or 4 mm in diameter) version
of a cookie cutter, is used to cut out a cylindrical piece of skin.
The hole is typically closed with a suture and heals with minimal scarring.[Ref]
The Shave
Biopsy
In a shave biopsy, only the outer protruding part of the suspect mole
is removed. A local anesthetic is injected. Then a sharp scalpel is
used to cut off the top part of the mole protruding above the skin.
[Ref]
With all biopsies
where melanoma is a possibility, care must be taken to ensure that the
full thickness of the lesion is included in the biopsy specimen because
treatment and prognosis is critically dependent on accurately assessing
the depth and level of invasion of the lesion into the lower layers
of skin. For this reason, a shave biopsy should not be performed
because this technique fragments the lesion, preventing accurate
assessment of the depth and thickness of the melanoma.[Ref].
The Biopsy
Report
After the biopsy, the dermatologist will send the collected specimen
to a pathologist who will prepare a biopsy report for your physician
describing the results of the examination of the biopsy specimen. You
can and should request a copy of this report as it contains valuable
information that you may need to refer to in the future.
Another word of
caution here. The pathological diagnosis of melanoma is notoriously
difficult. For this reason, it is generally recommended that
the pathology test for a suspicious mole be done by a dermapathologist
as they receive specialized training in the detection of skin tumors.
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