Information on the skin biopsy
Biopsy techniques
Advantages of the sharp biopsy
Sharp extraction of biopsates has the advantage
compared with other procedures that the tissue is only slightly
damaged, and can thus be properly assessed histopathologically.
Older sharp spoons are often less sharp than the name would
suggest; their use frequently leads to massive 
fragmentation
and contusion of the tissue. When removing skin changes with
a laser or the electric loop, serious artifacts often arise,
which can make a histopathological classification impossible.
A prospective study of the suitability of histopathological
preparations for assessment in women with cervical intra-epithelial
neoplasia showed that over half of the preparation obtained
with the
electric
loop or
CO2-Laser
could either be given only a limited assessment, or else none
at all, whereas this was never the case with preparations
obtained by sharp conisation.(17)
But it is essential to be able to make an
assessment! In the first place, the
question
regarding whether removal is complete in the case
of malignant tumours can only be answered if the edge of a
biopsy has not been artificially damaged. Following electro-dissection,
the recidivism rate as a result of current artifacts at the
edges of biopsies is significantly greater than is the case
with removal using a sharp blade.(7) On the other hand, faulty
clinical diagnoses are sometimes inevitable, even with experienced
dermatologists. In early melanomas, for example, in several
studies a diagnostic accuracy rate of only about 75% was found,
and even in the case of changes that were actually removed
from purely cosmetic indications, faulty clinical diagnoses
still arose: fibrous face birthmarks can be mistaken for malign
adnex tumours, angioma of high-vessel sarcomas, seborrhoeic
keratoses of malign melanomas and pendular fibromas of fibro-epithelial
basal-cell carcinomas or
papillomatous
amelanotic melanomas. In the USA, the increasingly
common malpractice lawsuits in dermatology are not infrequently
brought about by inadequate biopsies; where there is a faulty
diagnosis, both the clinician and the histopathologist are
drawn into the litigation. A histopathological diagnosis confirmation
with the aid of a sufficiently large preparation, removed
using the sharp method, is therefore absolutely essential!
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