Endometriosis (growth of the uterine lining)

Endometriosis is a benign growth of the lining of the uterus called the endometrium. Under normal circumstances, the endometrium is located exclusively in the uterus (uterine cavity), but in endometriosis the endometrium also grows in other places in the female body. The most commonly affected areas are the outer uterine wall, the connective tissues of the uterus, and the ovaries.

Endometriosis can also occur on the peritoneum (lining of the abdomen), which surrounds most organs in the abdominal cavity, but less commonly on organs (such as the bowel or urinary bladder) themselves.

The degree of endometriosis can vary greatly - usually only pinhead-sized growths appear on the peritoneum, but large blood-filled cysts can also develop, especially on the ovaries. In the case of very pronounced endometriosis, adhesions between the uterus, fallopian tubes, ovaries, intestines and urinary bladder are also possible.

There are no reliable figures on the frequency of the disease, but it is estimated that about 4 to 12 percent of all women develop the disease between puberty and menopause.

Despite intensive research, the exact cause of endometriosis is still unclear. One assumption regarding the development of endometriosis is that the interplay between various hormones and the immune system is altered in such a way that the immune system can no longer successfully prevent cells from multiplying in the wrong place in the body.

The following theories are considered most likely to explain how endometriosis lesions develop:

• Sampson's transplantation theory is based on the assumption that during menstruation loose endometrial cells are carried away through the fallopian tubes (but also through the blood, lymph vessels, or surgery) and settle in another location.

• According to Meyer's metaplasia theory, endometriosis lesions arise directly in the wrong place from embryonic abdominal cavity cells.

• The induction theory is a mixture of the transplantation and metaplasia theories.

Since the growth of endometriosis is very strongly dependent on the influence of estrogens, the disease is very rare in prepubertal girls or in women in menopause (menopause).

The main symptom of endometriosis is cramping pain associated with the menstrual cycle, which increases in intensity from time to time. However, about 50 percent of all those affected suffer from no symptoms at all.

The following complaints, among others, can occur with endometriosis:

• Dysmenorrhoea (severe pain during menstruation)

• pain in the lower abdomen independent of menstruation

• Nausea

• Pain during sexual intercourse (dyspareunia)

• Childlessness

• discomfort when urinating or having a bowel movement (rather rare)

Endometriosis is often diagnosed successfully relatively late - 3 to 11 years after the first symptoms. The younger the sufferers, the later they are successfully diagnosed with endometriosis. In about half of the cases, patients have seen five or more doctors because of the symptoms before a correct diagnosis is finally made.

The reason for the late diagnosis is that the non-specific symptoms, such as menstrual cramps, are sometimes considered normal by both the patients and the doctors.

Diagnostic methods include a gynaecological examination, laparoscopy (abdominal endoscopy) or ultrasound (although only cysts on the ovaries can be reliably detected). Laparoscopy is the only method for a reliable diagnosis. Under general anaesthesia, surgical instruments are inserted through a small incision in the navel to examine the abdominal cavity and remove any endometriosis lesions.

Whether a laparoscopy should be performed depends primarily on the extent of the symptoms and should be clarified in a detailed discussion between the patient and the doctor.

Whether endometriosis should be treated always depends on the severity of the symptoms. An accidentally discovered, symptomless endometriosis therefore does not necessarily have to be treated. A distinction is made between the following treatment components:

Surgery: this is a sensible therapy, especially in the case of severe symptoms or an unfulfilled desire to have children. The endometriosis lesions are usually removed during a laparoscopy (see subsection "Diagnosis") or through a larger abdominal incision. The risk of recurrence is relatively high despite successful surgery - in many treated women, endometriosis lesions and associated symptoms reappear after several years. It is sometimes recommended that the risk of recurrence be reduced by subsequent hormone treatment, but there is as yet no scientific evidence of the effectiveness of hormone therapy.

Drug therapy: A distinction must be made here between pain therapy and therapy for endometriosis. Conventional painkillers are used to treat the pain, whereas hormone preparations are used to prevent the progression of endometriosis. Gestagens or so-called GnRH analogues (gonadotropin-releasing hormone analogues) are mainly used, which have the effect of reducing or completely stopping oestrogen production in the ovaries for the duration of the treatment. This causes the endometriosis lesions to recede and the symptoms to decrease. However, this type of therapy is not suitable for women who wish to have children and are infertile due to endometriosis.

Even after successful therapy, endometriosis is a disease with a high relapse rate. In most cases it is possible to temporarily alleviate the symptoms - however, as in many cases after discontinuation of the drug treatment the symptoms recur with varying degrees of severity, regular check-ups are necessary.

With the onset of menopause and the associated changes in the female hormonal balance, endometriosis usually regresses on its own.

According to current knowledge, there is no way to prevent endometriosis. The only thing that can be done is to consider the possibility of endometriosis in case of any symptoms such as increasing/decreasing pain during the menstrual cycle (which, however, does not necessarily have to be the cause of endometriosis) and to have this clarified by the attending physician.