**1. Introduction**

30 Endometriosis - Basic Concepts and Current Research Trends

[131] Pellicer A, Valbuena D, Bauset C, et al. The follicular endocrine environment in

[132] Redwine DB. Conservativela paroscopice xcisiono f endometriosisb y sharpd

Fertil Steril 1998;69:1135-1141

Steril 1991;56:628-634

stimulated cycles of women with endometriosis: steroid levels and embryo quality.

issection:life table analysis of reoperation and persistent of recurrent disease. Fertil

Endometriosis is defined as the presence of functional endometrial tissue in an ectopic site (outside of the uterus). Although endometriosis is usually confined to the ovaries, uterosacral ligaments, and cul-de-sac, it has been documented in almost every organ system in the body.

Endometriosis was first described by Russel in 1955. Endometriosis is a common disorder of the female reproductive organs and is the leading cause of chronic pelvic pain in women.

It is one of the most complex and least understood diseases in their field and, despite many theories, we still do not have a clear understanding of its causes.

There is no relationship of endometriosis to race or socioeconomic status but it has a strong familial link. If sister or mother of a woman has the condition, then she is approximately five to six times more likely to develop it.

Because ovarian function is necessary for the development and maintenance endometrial implants, endometriosis has been reported only in the reproductive ages and so, is normally not seen before age 15 or after menopause. Endometriosis is most common in women between the ages of 25 and 35. However, after menopause, there are two factors which may promote or maintain endometriosis. One is the use of estrogen replacement therapy and the other is the presence of high endogenous estrogen in obese patients.

There have been several case reports of histological endometriosis in men , all of them in the prostate. These have occurred all in men with cancer of the prostate who were undergoing high-dose estrogen therapy.

The prevalence of endometriosis in specific categories of patients has been reported (Table.1), but the prevalence in the general population is not definitely known because a majority of patients are asymptomatic. It is estimated that affect 10% to 20% of women of reproductive age, with a peak incidence in the mid-20s. However, in women with severe menstrual cramps, the incidence of endometriosis has been reported to be between 25 and 35 percent.

Although endometriosis is a benign condition but it may have an aggressive clinical behaviour. Many women with urinary tract endometriosis have few or no symptoms. Some present with infertility. Other manifestations include urgency, frequency, pain on passing urine, pain in the flank or the back region or recurrent urinary tract infections. Some women

Urinary Tract Endometriosis 33

The pathogenesis of endometriosis has not been definitively established but predominant

• **The implantation theory:** This theory proposes that endometrial cells are either transported during menstruation through the fallopian tubes and implanted on pelvic structures (transtubal regurgitation or retrograde menstruation) or are transplanted to

• **Lymphatics and blood vessels dissemination:** This theory is specially useful for explanation of endometriosis at locations outside the pelvis(extraperitoneal disease). • **Coelomic metaplasia:** This theory proposes that the peritoneal cavity contains undifferentiated cells capable of differentiating into endometrial tissue. It is said that repeated inflammation may induce metaplasia of mesothelial cells to the endometrial

Genetic factors probably influence an individual's susceptibility to endometriosis. The possibility of a familial tendency for endometriosis has been recognized for several decades. If a woman has endometriosis, a first-degree relative has a 7 percent likelihood of developing the disorder as compared with 1 percent in unrelated persons. Concordance in

There is evidence for altered humoral and cell-mediated immunity in the pathogenesis of endometriosis such as Deficient cellular immunity, improper Natural killer cell activity and increased concentration of leukocytes and macrophages in the peritoneal cavity and ectopic endometrium. These variations in immune system may result in an inability to recognize the presence of endometrial tissue in abnormal locations, decreased cytotoxicity to autologous ectopic endometrium and finally, secretion of cytokines and growth factors by leukocytes

One hypothesis is that secretion of various cytokines by inflammatory cells into the peritoneal cavity leads to proliferation of implants and recruitment of capillaries. Oxidative stress may be another component of the inflammatory reaction. Thus, the immune system may play a role in determining who will develop endometriosis, as well as the extent and

It is said that these women had higher rates of autoimmune inflammatory diseases, hypothyroidism, fibromyalgia, chronic fatigue syndrome, allergies and asthma, compared with the general female population so, it could provide support for the theory of altered

Vesical endometriosis is said that may be due to bladder adenomyosis or an extension of adenomyosis from the uterus into the bladder or because of imperfect closure of the uterus

The risk of endometriosis developing into a cancerous lesion is very low(1 - 2.5%) and the

Endometriosis is a common, benign, chronic, estrogen-dependent disorder with a relapsing/remitting nature. The endometrial tissue acts just like the normal ones in the uterus, responding to cyclical hormone levels, growing and bleeding at certain times of the cycle. If the tissue is in the ovaries, then bleeding of it results in accumulation of blood,

and macrophages into the peritoneal fluid of women with endometriosis.

surgical scars (episiotomy, laparotomy) as a result of surgery or delivery.

hypotheses are as follows:

epithelium.

twins has also been observed.

clinical manifestation of the disease.

during a cesarean delivery.

immune system in women with endometriosis.

same as normal endometrium and ovaries.

have cyclic hematuria at times of menstruation. Some patients give a history of gynecologic surgeries such as hysterectomy many years ago.


Table 1. The prevalence of endometriosis in women groups of reproductive age.

It can be associated with many distressing and debilitating symptoms may be asymptomatic, and incidentally discovered at laparoscopy or exploratory surgery. Usually, endometriosis is confined to the pelvic and lower abdominal cavity; however, it has occasionally been reported to be in other areas. Endometriotic lesions of the urinary tract are present in 1 to 4 percent of women with endometriosis and often coexists with disease at other sites of the body.

Although ureteral and bladder endometriosis both occur in the urinary tract, they do not frequently coexist and their clinical presentation and management are different. Bladder endometriosis often mimicks recurrent cystitis, but rarely results in severe sequelae. Ureteral endometriosis is often asymptomatic, but can lead to silent loss of renal function. Renal and urethral involvements are rare and only as case reports.


Table 2. The prevalence of endometriosis in urinary tract.

The optimal way to diagnose endometriosis is by direct visualization and biopsy of the implant(s) anywhere through the body.
