A testis biopsy is
done in order to find out whether sperm production in
the testis is normal or not. This is the "gold
standard" for judging testicular function, since
here the testicular tissue is being examined directly.
How is a testicular biopsy performed? This is a simple
surgical procedure, which can be done under a local
anaesthetic, in an operation theatre or even in the
doctor's clinic, if it is well equipped. The test takes
about 5-10 minutes to be carried out; and a biopsy could
be taken from just one testis, or from both testes,
depending upon the nature of the problem.
The removed bit of tissue is then placed in a special
preservative fluid called Bouin's fluid which is then
sent to a pathologist for examination under a microscope
after staining.
The biopsy surgery doesn't hurt, because the local
anesthetic numbs the tissues. There may be dull ache
for a few days after the procedure, but this can be
relieved by mild analgesics.
Since testis biopsy is a surgical procedure, most doctors
would use it as the last resort when testing the man.
If you are advised to have a testis biopsy, ask the
doctor how the result will change your treatment (a
question you should ask before being subjected to any
medical test, in fact!).
The only group of infertile men who should be offered
a testis biopsy are those with azoospermia. Men with
oligospermia should not be subjected to a testis biopsy
because the biopsy report is always normal in these
men (and this is not surprising - after all, since sperm
are present in the semen, they are obviously being produced
in the testes!)
Formerly, when doctors performed a testis biopsy, they
would send only one chunk of tissue for testing. However,
today we know that a single biopsy may not be representative
of the entire testis. Sperm production is not uniformly
distributed throughout the testis, especially in men
with non-obstructive azoospermia because of testicular failure.
The key question we need to answer in these men is : do
they have complete testicular failure ( no sperm
production at all in the entire testes) ? or partial
testicular failure ( sperm being produced in a few areas
of the testes, but the amount produced being so little,
that they cannot reach the ejaculate, as a result of
which the sperm count is zero) ?
This means that in order to
get a true picture of sperm production in the testis,
the doctor needs to sample at least 4 different areas
of the testis, all of which need to be examined.
In the past, a testis biopsy was purely a diagnostic
procedure. Today, it is also used to retrieve testicular
sperm in order to treat men with severe male factor
infertility. These testicular sperm can be used for
intracytoplasmic sperm injection (ICSI). Specialised
infertility clinics also have the ability to freeze
the testicular tissue. This testicular sperm freezing
can be very useful, especially in men with small testes,
as the biopsy does not need to be repeated again during
treatment.
The interpretation
While the biopsy is an easy test to perform, it is difficult
to interpret properly, unless done by an expert. The
doctor looks for evidence of sperm production in the
seminiferous tubules. In some cases, there is no sperm
production at all (absent spermatogenesis); or the sperm
production is arrested at a particular stage (maturation
arrest). This implies testicular failure, which is usually
irreversible, and there is no treatment for this malady.
The key question is whether there is partial testicular
failure; or whether the testicular failure is complete,
which is why examining multiple areas of the testes
is important. Men with complete testicular failure have
no sperm production at all in the entire testes. Men
with partial testicular failure will have a few areas
of their testes which still produce sperm normally.
These sperm can be used for
TESE-ICSI treatment. However,
their testicular sperm production is so poor , that
the testicular sperm do not reach the ejaculate, as
a result of which the sperm count is zero.
If, on the other hand, sperm production in the testes
is completely normal, and yet there are no sperm in
the ejaculated semen, this clearly means that there
is a block in the male reproductive tract. This is called
obstructive azoospermia, and is the one condition in
which a testis biopsy is extremely useful (i.e., in
the evaluation of the azoospermic male, to determine
if there is a block to sperm transport).
A testis biopsy is often a procedure which is done
badly because it is so "minor" so beware!
It is preferable that the biopsy be done by a specialist;
a poorly done biopsy may make reconstructive surgery
on the epididymis more difficult later on, by causing
adhesions and fibrosis (scarring). The commonest problem
with the biopsy, however, is that the biopsy result
is not reported accurately by the pathologist. Interpreting
a testis biopsy is difficult and requires special expertise
and is not something that the ordinary pathologist does
well. You should retrieve and retain your own slides
and preserve them carefully. The pathology laboratory
can also be instructed to keep the tissue ("blocks")
carefully. It is unfortunately common to find that a
testis biopsy has to be repeated simply because the
first one was done so badly that its results could not
be accurately interpreted. It may also be a good idea
to get a second specialist's opinion on the testis biopsy
slides.
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