What is Adenomyosis?
Adenomyosis is defined as 'the presence of endometrial
tissue within the myometrium.' (The myometrium is the
medical term for the muscular portion of the uterine
wall.) In the past, adenomyosis was referred to as “endometriosis
interna” in the medical world, and sometimes as “inside-out
endometriosis” in lay terms. What we commonly call
'endometriosis' can also be called 'endometriosis externa'.
Adenomyoma is the name given to an area of adenomyosis that is encapsulated by
myometrial tissue. Because of the presence of adenomyosis, this complex of tissue
is differentiated from a myoma, or fibroid tumor.
 How Does Adenomyosis Get There?
The bottom line is, we do not know! In 1908, an investigator named T. S. Cullen
concluded that adenomyosis was an evolving invagination of the surface epithelium.
That means he thought it was an ingrowth of the endometrium from the
inside
of the uterus. This is one theory.
Some reports have shown that the frequency of adenomyosis
is greater in patients who have undergone cesarean sections
and intrauterine instrumentation. This is another theory.
A third theory involves metaplasia, that cells that were
intended to be inside the uterus never got there. It
does seem likely that retrograde menstruation is not
a probable cause.
How Is Adenomyosis Diagnosed?
The diagnosis can only be proven by the pathologists.
This requires the microscopic evaluation of the uterus
or tissue taken from the uterine wall.
Although it is possible for a surgeon to make the diagnosis
by core-type needle biopsy, the sensitivity is very low.
Unless an adenomyoma changes the natural contour of the
uterus, the surgeon has no visual clues as to where the
adenomyosis is. Therefore, accurate diagnosis would require
multiple biopsy sites going deep into the uterus, plus
a generous helping of luck.
Lately, we have heard the claim that MRI can diagnose
adenomyosis.
MRI should be expected to be excellent in recognizing
uterine masses like fibroids, cysts, and adenomyomas
if they reach 5 mm. or greater in size. We expect that
it will also add to the ability to differentiate among
any of the above. MRI may be able to lead us to expect
adenomyosis if the myometrial thickness is increased
or the consistency of the myometrium is changed.
Unfortunately, this type of information will probably
remain quite nonspecific. We are not hopeful that we
will soon be able to rely on it to diagnose the isolated,
scattered areas of glands lost among the muscle cells
because of their small size. Much work is ongoing to
get more information as to the diagnostic accuracy of
this technique.
Ultrasonography or MRI may identify glandular islands
in the myometrium. But as with pelvic endometriosis,
the ultrasound can't usually be specific enough to diagnose
endometriosis to the exclusion of other possibilities.
A good gynecologist may suspect adenomyosis based on
the clinical factors described below, but the final diagnosis
usually has to wait until hysterectomy is performed.
What Are the Symptoms?
Much of the time, a woman has few or no symptoms. However,
as the condition worsens, many women begin to be troubled
with heavy menstrual bleeding and increasing cramps.
On physical examination, a soft, boggy enlargement of
the uterus may be detected and we observe an unusual
type of tenderness on pelvic exam when the uterine muscle
is compressed.
Some adenomyomas are exquisitely tender to touch on pelvic
examination and during intercourse.
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What Causes Cramps and Heavy Bleeding?
The function of the uterine muscle during normal menstruation
is to provide a coordinated involuntary contraction.
This contraction reduces the volume of the endometrial
cavity and pinches off the large blood vessels passing
through myometrium.
With adenomyosis, the presence of many tiny islands of
functioning endometrial glands scattered in between the
normally tightly laced muscle bundles creates numerous
little pressure points that can be extremely tender.
This creates pain that is worsened when the muscle is
contracting. In addition, the efficiency of the contraction
is reduced. You can get a sense of what's happening if
you imagine the uterus as a person with a mouthful of
marbles who is trying to spit. Because the uterine muscle
contractions aren't as efficient as they should be, the
resulting menstrual flow is heavier.
Most very heavy menstrual bleeding does not mean
that a woman is shedding substantially more endometrium.
The 'endometrial slough' is determined by the size of
the uterus and the hormonally induced endometrial thickness.
The uterus has large blood vessels that come through
the myometrium to feed and supply the endometrium. Really
heavy bleeding occurs when the uterine muscle cannot
do its job of contracting around these vessels. This
is important because after the endometrium is passed
out; the basalis layer may be very thin, which could
expose the raw muscle surface. This means that the large
vessels can pump blood directly into the uterine cavity
of the muscle cannot contract well.
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Can Adenomyosis Fool You?
Yes! The diagnosis of uterine fibroids has been made many times, only to find
out later that the obvious irregularity on the uterus was an adenomyoma.
In our experience when a patient has requested hysterectomy after conservative
surgery for endometriosis that has failed to control severe dysmenorrhea (cramps)
or central pelvic pain, frequently adenomyosis has been found in the uterus.
Is Hysterectomy the Only Option?
Conservative treatments can be tried. Cryo-endometrial ablation can be performed.
This will sometimes result with good symptom relief.
The disease is scattered invisibly throughout or very deep in the uterine muscle.
Attempts to control the symptoms of deep adenomyosis with endometrial ablation
have not been uniformly successful. Most of the time the decision to perform
a hysterectomy is made by the patient who comes to the point that conservative
avenues of treatment have been tried and found unsatisfactory and quality of
life has declined to unacceptable levels.
Can the Pain and Bleeding be Controlled?
Non-steroidal anti-inflammatory drugs (NSAIDS) are generally excellent prostaglandin
inhibitors. Because prostaglandins stimulate the uterine muscle to contract,
reducing these compounds may be of great help. These drugs must be started early
in the menses and continued regularly to be effective.
Depo-provera will stop all menses. It will usually control the heavy bleeding
and cramps but not always the tenderness. The benefits of this drug must be balanced
by the cost, side effects, and desire for fertility.
LH-RH agonists and antagonists (Lupron injections) are used to also reduce symptoms
temporarily, if the expense and side effects can be tolerated.
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