- Anatomy
- The penis and the scrotal pouch (Latin: scrotum),
holding the testicles (balls, eggs (Ger.)), together constitute a token that characterizes
the male human. The word testicle does have something in common with the word testament.
The Latin word testis also means witness; in Roman days, someone without testicles
was definitively not a man and could therefore not testify.
The scrotal pouch is in fact a relatively simple pouch, made
of rather thin skin, but with a definite muscle sheet underneath - that is the reason why,
if necessary, the scrotal pouch can make itself somewhat smaller. Inside, the pouch is
divided into two smaller pouches, each containing one testicle with its epididymis. An
epididymis is connected to the testicle and overlies it like a cap; it contains a very
large amount of microscopically small tubes. From the epididymis, the vas deferens will
conduct the freshly made sperm cells to the area of the prostate. The vas deferens runs
together with blood vessels that supply blood to and from the testicle and some muscle
fibers; as a sort of long thin sausage they perforate the abdominal wall at the groin.
Since, from the standpoint of the abdomen, the testicles are located 'outside' the body,
there must be a tiny hole in the abdominal wall there to let the vas deferens in: early,
or later in life, a hernia may form at this weak spot. Right behind the prostate the vas
deferens joins the outlets of the seminal vesicles to be able to leave the body through
the urethra as semen, in search of a female egg cell.
- Functions of this organ
- Like so many other organs in our body, the testicle has its
identical counterpart - one never knows, mother nature must have thought. The left and
right testicle (plus everything that goes with it) have exactly the same function. Unlike
what some people think, nothing is held in reserve; both testicles are active, although,
in normal circumstances, one testicle is sufficient.
The testicles have two functions:
The production of testosterone,
the male sex hormone. A hormone is a substance, a molecule, that acts as a
messenger in the blood. Since the blood flows through the entire body, the hormone in it
will also reach every spot in the body; some organs, that are susceptible to the hormone,
will then be told to do something. Testosterone will cause a boy to change into a man
during puberty: he will grow a beard, his voice will get a lower pitch, his penis will
grow, he will be able to have erections and will develop feelings of (male) lust. Of
course, it is clear at a younger age that the child is a boy and not a girl (that
difference is coded into the genes), but only after puberty started off - in girls usually
somewhat earlier than in boys -, the hormone production is increased and male
characteristics enhanced. Later in life, the hormone production will remain relatively
constant, although it wears off at old age. Despite a lot of positive effects of
testosterone, there also exist negative ones: it causes baldness in some men and may lead
to growth of the prostate and may play a role in the development of prostate cancer. The
level of testosterone in the blood varies from day to day and from one man to another. A
higher testosterone level does not cause more feelings of lust, nor a bigger penis, nor a
higher chance to develop cancer. Hormones are usually needed in very small quantities -
testosterone is no exception; without too much problems, one testicle can be missed - the
other will produce sufficient amount of testosterone. There exist, however, other male sex
hormones in the body, which play a lesser role; these hormones are made in the adrenals,
which also produce - in males too - female sex hormones.
Other cells inside the testicle are responsible for the
production of sperm cells, millions each day. Production of sperm cells will
continue day and night, so not only during ejaculation. The sperm cells can, however, be
temporarily stored behind the prostate in the seminal vesicles. Sperm cells will last a
long time; most cells in the semen are some two months old. After ejaculation, it takes
about three days to get the semen back to normal (numbers of sperm cells) again. Sperm
cells are self-supporting and have their own engine in the form of a twisting tail. In the
head of the sperm cell half of the total amount of genetic information needed to build a
complete human is stored; the other half is supplied by the female egg cell. The
production of sperm cells is 'on full ahead' all day long, while one cc of semen can
easily contain 40 million sperm cells or more. Quality control is something to be desired,
however, since about half the amount of sperm cells are not built well or malfunction;
obviously, mother nature thinks that quantity is more important than quality - only one
sperm cell is needed to mix with the female egg cell. After a sperm cell ha been made in
the testicle, it will need to grow into an adult cell, capable of fertilizing the egg
cell; this maturation process takes place in the labyrinthine tube system of the
epididymis. Harboring the maturation process of the immature sperm cell is the only
function of the epididymis. When the sperm cell has grown up, it is further transported
through the vas deferens in the direction of the prostate.
Beneath the skin of the scrotal pouch and in the stem that
contains the vas deferens and blood vessels towards the testicle a lot of tiny muscle
fibers can be found. If the testicles (and with it, fertility) are in danger, for example
in extreme cold, but also in fright, these muscles come into play and contract; this
causes the scrotal skin to ripple and get thicker, while the testicles are pulled up close
to the warm and protecting body.
It is still not clear why mother nature has placed the
vulnerable testicles more or less outside the protective body. Probably it has something
to do with the production of sperm cells, which is perhaps more efficient while the
temperature in the testicles is a bit lower than 37 degrees Celsius.
- What are the signs and symptoms of the condition?
- Diseases of the testicles can be divided into several
categories:
Inborn errors:
In cryptorchism,
the testicle is not located at its right place in the scrotal pouch. Right after
conception, when we people are just starting off, a lot of thing are going on a clump of
cells that later becomes our body. Organs are made, relocated, made smaller or larger, or
can disappear again. At first, the testicles are located at a spot in our future body
where, in adult life, our kidneys will be; in order to get into their right place in the
scrotal pouch, they will have to move 'downwards'. Sometimes something goes wrong and one
or both testicles end up somewhere else in the body - its gets stuck somewhere on its way
down. Usually, if it does get stuck, it can be found in the groin (almost there), but in
some cases it is still inside the abdomen. In all of these cases of cryptorchism it is
necessary to correct this surgically at a young age to prevent malfunction of the testicle
at a later age.
A hernia in a child is
always inborn, i.e. it was already there at birth. On its way from the 'kidney region'
towards the scrotal pouch (see above), the testicle will need to pass the abdominal wall
at the groin. Long before birth, a small hole is formed there to let the testicle pass.
After passage, this hole is supposed to get smaller again, so that it is just big enough
for the vas deferens and some blood vessels. Sometimes, however, this opening is left too
big, so some of the inner lining of the abdomen can bulge out once the pressure inside get
higher after birth (for example by crying). This is called a hernia. Since this can also
be considered a disorder in the 'lowering' of the testicle, a hernia in a child is often
associated with cryptorchism.
Diseases of the epididymis:
An infection of the
epididymis is often associated with an infection of the prostate. Between
epididymis an prostate a connection exists in the form of the vas deferens, which contains
sperm cells, but also nutrition for them. Bacteria like this food too and can easily creep
up from the prostate to the epididymis. An infection of the epididymis is rather painful
and can lead to general sickness and fever. It can cause scar tissue to form and
obstructions of the tubes inside, which in turn can lead to a decrease of fertility. Also
a cyst, a small cavity filled with liquid, may form in the epididymis; this complication
is called a spermatocele, which can
cause irritation if it gets large enough. Different types of bacteria may play a role in
these infections; venereal diseases, like gonorrhea, may sometimes cause violent
infections of the epididymis.
An obstruction of
the tiny tubes inside the epididymis may block the passage of sperm cells that maturate
there. The result is a decrease in the number of sperm cells that eventually reach the
prostate and , therefore, lower sperm counts in the semen and a decrease in fertility,
although, in normal circumstances, the other testicle/epididymis should be able to produce
enough sperm cells to ensure normal fertility.
A
Spermatocele
is a (usually) small cavity, filled with watery liquid, in the epididymis. A lot of men
have one or more small Spermatocele in one or both epididymis, probably the result of
infection's) long ago, which often go virtually unnoticed. Usually, a
Spermatocele does
not cause pain or discomfort, unless it becomes very large, in which case it may cause
irritation because it is 'in the way'. Sometimes they may reach several inches in diameter
and cause irritation while walking. However, Spermatocele mostly remain small and never
give any trouble; since Spermatocele are quite harmless and almost never give rise to
complications, it is best to leave them alone and avoid therapy that does.
- Diseases of the testicle:
- A small testicle may be inborn, i.e. present at birth, or
caused later in life, for example by infections. Usually, an infection only affects the
epididymis. Mumps, if caught in adolescence, may, however, cause infection of the testicle
itself. Fortunately, this complication is seldom seen nowadays. An infection of the
testicle can cause problems regarding to the production of sperm cells and may, if both
testicles are infected, lead to infertility. In that case the affected testicle will
become smaller. The hormone production
is usually less affected.
An accident may also cause damage to the testicle and the
formation of scar tissue, while a testicle that is not in its right place, i.e. in the
scrotal pouch, does not develop well and will grow insufficiently during puberty.
Cancer
of the testicle is, fortunately, a rather rare disease. Unfortunately, it usually strikes
young men between 16 and 30 years of age, although it is sometimes seen in elderly men. It
is also an aggressive cancer, which grows quickly and spreads early an easy, which makes
treatment difficult and time-consuming. A lot of young men have an enormous sense of shame
about problems in this area of the body and fail to go to the doctor quickly; since the
tumor is usually painless, they often think that it is not serious or, even, that they
have picked up a venereal disease. All of the above often leads to a late visit to the
doctor and a late start of therapy.
A tumor (cancer) of the testicle often shows itself by a fast
enlargement of the testicle. Usually, lumps or nodule can not be detected and it seems
that the testicle as a whole has grown bigger. As a rule, it is not painful.
Cancer of the testicle is often considered to be an inborn
disease of the testicle; the tumor has been there since birth, but only becomes active
during or right after puberty. This explains the youth of the patients. It also explains
the fact that it happens more often when the
testicle
has not come down nicely in the scrotal pouch, even if this has been surgically
corrected. This last fact is a good reason to search for a testicle that is not found in
the scrotal pouch or groin; if it is located somewhere in the abdomen, it has a high
tendency to lead to cancer, which is not detected until late in the disease, when it has
already spread to other parts of the body. If one testicle has been found to contain
cancer, the chance that the other will be affected too is higher.
A
Hydrocele
is a swelling of (part of) the scrotal pouch because of an increased amount of moist
around the testicle/epididymis. Every testicle epididymis has its own little pouch, which
contains a little bit of moisture, so the testicle can move around a bit. Several causes,
including inborn ones, may lead to an increase of the amount of liquid, causing the
scrotal pouch to bulge. This condition is harmless, but may cause irritation when the
bulge becomes too big. There is no cancer involved and it does not lead to cancer either.
Infertility may have
several causes:
The production of sperm cells is too low or
non-existent. This may be inborn, like in cryptorchism
or caused by hormonal disorders; in these cases the testicle is usually small. It may also
have been developed at a later date, for example by an infection with mumps (not in
childhood). Of course, in order to lead to a diminished fertility it is necessary that the
other testicle is insufficient too, since one normal testicle
epididymis should be enough
for normal fertility.
An obstruction further along the way;
the sperm cells are produced in normal numbers but the exits are blocked. The obstruction
is often located at the level of the epididymis for example due to an infection, but a
block may also exist in the vas deferens. Sometimes, this is meant to be, like in
sterilization, but it may also be inborn. An obstruction may also exist at the level of
the prostate.
Because of an
infection
of the epididymis the maturation of the young sperm cells may be hampered, which leads
to a loss of quality and 'effectiveness' of the semen, although a normal number of sperm
cells exist.
A Varicocele
is
a disorder of the small veins, that run the blood from the testicle back towards the
heart. Usually there are one or two big blood vessels, collecting the blood from the small
network around the epididymis and vas deferens, and running upwards to connect to the
bigger veins further ahead. To prevent blood flowing back towards the testicles, valves
are inserted into these veins, which prohibit backflow. Sometimes, these valves are
malfunctioning, causing backflow (especially in the upright position, helped by gravity,
and during exercise) and subsequent enlargement of the small vessel network in the scrotal
sack. This phenomenon feels like "a bag of worms". Since the malfunctioning
veins are almost trice as long at the left side than at the right,
Varicocele is almost
invariably left sided. Malfunction of the valves is usually inborn, but does not show until
puberty or later, when the testicles are matured. The disease may give rise to dull pain,
especially during exercise. There is still debate whether it may constitute a reason for
decreased fertility. On the one hand, some cases of diminished fertility have improved
after therapy, although many have not. On the other hand, many men have
Varicocele without
knowing and without fertility problems, while one normal testicle (on the other unaffected
side) should be enough to preserve normal fertility. In many cases of decreased fertility,
the cause is unknown, so, when the patient is found to have Varicocele, the fertility
problem is linked to this for lack of another possible cause.
- Examinations
- There is not a large number of tests available for the scrotal
pouch.
The physical examination
(the look and feel) of the scrotal pouch usually gives a lot of information about it. It
is easily shown whether the testicles are at their right location in the pouch, if they
are to big or too small, or painful. The presence or absence of a
Hydrocele, Spermatocele
or hernia can be checked.
Cancer of the testicle can usually be ruled
out, although the physical examination is not always conclusive. If an infection of the
epididymis is present, the epididymis is usually painful; it may sometimes be a sign of a
concurrent prostatitis. The vas
deferens can usually be felt and checked quite easy.
Blood samples are useful
to detect the level of testosterone (the male sex hormone) and may have its use to measure
certain substance in relation with cancer of the testicle.
Urine examination can
be important to exclude an infection of the bladder, prostate or
epididymis. In a number of cases it will
be necessary to use a cotton stick to 'scrape' some material (cells, bacteria) from the
urethra, to be further examined in the lab. In this way, Gonorrhea or Chlamydia
infections can be checked.
Semen examination will
show the number and quality (motility) of the sperm cells, for example in case of
infertility. In normal circumstances,
millions of sperm cells are produced each day, but not all of them are of good quality;
mother nature relies on the 'law of large numbers' to ensure pregnancies. There are big
differences in the number of sperm cells per cc. from day to day and from one man to
another (between 20 and 80 million per cc.) while a large number of sperm cells does not
equal a high fertility - if only because a high fertility needs two people. About 50-70%
of all sperm cells are active and (as far as we can tell) healthy. The number of white
blood cells (=inflammation cells) can also be counted in semen and a culture can be done
to confirm an infection.
Using ultrasound
(like SONAR in a submarine) an image of the inside of the scrotal pouch and its contents
can be made. The examination is painless. Using this technique it is possible to get an
impression of the extent of cancer of the
testicle and the presence or absence of a
Hydrocele
or Spermatocele can be confirmed.
In some cases, for example in case of infertility, it may be necessary to take
a tissue sample (biopsy) of one or both testicles in
order to get information about the quality of sperm cell production; this examination is
usually done under general anesthesia.
- What are the treatments?
- It is impossible to present all possible therapeutic options
for all diseases of the testicles. More frequent forms of treatment will be mentioned.
Treatment of an infection of the epididymis depends of course on the cause, i.e.
the type of bacteria involved. For an 'ordinary' infection other kind of antibiotics are
needed than for a venereal disease like gonorrhea. Also, the question whether there is
another infection present, like an infection
of the prostate, needs to be answered; if present, this needs to be treated too.
A
Hydrocele
or Spermatocele only needs to be
treated surgically if it causes discomfort or pain, usually because of its size. In the
past, a common practice was to empty the 'celled' by puncturing it with a needle and drawing
out the liquid with a syringe, but it often resulted in only a few days of relief, since
the 'celled' quickly filled with liquid again. Together with the needle, sometimes bacteria
entered into the formerly sterile environment of the 'celled' and caused infection.
Cancer of the
testicle needs to be treated as soon as possible, since the tumor grows very quickly
and spreads early and easily to lymph nodes and other organs like the lungs or the
abdomen. Treatment consists of removal of the testicle, while often a tissue sample is
taken of the other testicle to make sure that there are no cancer cells there. If
spreading of the disease has already occurred, than additional therapy is often necessary,
like radiotherapy or medicine to destroy all other cancer cells. Fortunately, the success
rate of treatment has gone up in the past years, even in advanced (spread) forms of
cancer. Unfortunately, a lot of patients wait a long time before going to the doctor, so
the disease has already spread. Because of the young age of most patients and the
aggressiveness of the therapy needed, there is a risk of infertility, necessitating semen
preservation before treatment (if there is still time).
Infertility
has many possible causes and, therefore, several possible therapies. If an obstruction of
the vas deferens exists, which needs to be treated surgically. An obstruction at the level
of the epididymis can sometimes be bypassed. Fortunately, it is nowadays possible to
artificially fertilize the female egg cell with only a few sperm cells; even one is now
enough. Infertility may also be caused by an infection, for example of the epididymis, which then needs to be
treated.
Fertility can sometimes also be a problem. Especially
when the family is 'complete' and there is no wish for further pregnancies. In that case,
sterilization may be an option if a definitive answer is sought. The procedure is far more
simple in male than it is in females and causes less complications. Under local
anesthesia two small cuts are made in the skin of the scrotal pouch, both vas deferens
are cut and the end tied. The drawing shows three examples; several techniques exist with
equal results - the choice depends on the personal preference of the urologist. Sometimes
the ends of the cut vas deferens are tied back, sometimes a piece of vas deferens is taken
out, sometimes the vas deferens is merely tied. The result is the same; near definite
infertility. The procedure seldom causes any complications.
Sometimes, for example in a new relationship, the want for
children reappears; the results of a reversal operation are, unfortunately, rather
disappointing.
Varicocele is usually
left-sided. In case of pain, attributable to the Varicocele, therapy should follow.
Sometimes, therapy is instituted in case of decreased fertility, where
Varicocele remains
the only possible cause. Therapy consists of blocking backflow from the bigger veins
downstream. This can be accomplished in three ways: plugging the vein's) using a small
catheter which is passed upstream from even bigger veins as far as possible and 'gluing'
the vein shut. A more conventional way is to operate, using a small incision, and
cutting/tying the vein. A third method is laparoscopy: using a small tube, with lenses,
the abdomen is entered and the vein(s) tied shut using small metal clips. After therapy,
other blood vessels will take over. All three methods are reasonable safe in experienced
hands and the results are about equal; the choice depends on the experience of the
urologist with a given method. The overall outcome is lowering of the blood pressure on
the small vessels in the scrotum, which has almost instant effect on the pain, if present,
while a possible effect on fertility, if any, may take several months. The small vessels
will, however, always remain somewhat enlarged due to the fact that they have been
stretched too far and will probably never get as small as they once were.
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