Endometriosis is a benign condition in which endometrial glands and stroma are present outside the endometrial cavity, usually in the ovary or on the pelvic peritoneum. It assumes great importance in gynecology because of its frequency, distressing symptomatology, association with infertility, and potential for invasion of adjacent organ systems, such as the gastrointestinal or urinary tracts. In addition, endometriosis often presents a difficult diagnostic problem, and few gynecologic conditions require such difficult surgical dissections.
The exact incidence of endometriosis is not known, but it is estimated that more than 15 per cent of women have some degree of the disease. It is noted in about 20% of gynecologic laparotomies, and of these it is an unexpected finding in approximately one half of the cases.
Generally, endometriosis is initiated in the third decade of life, becomes clinically apparent in the thirties, and regresses after the menopause. It may, on occasion, occur in infancy, childhood, or adolescence, but at these early ages it is almost always associated with obstructive genital anomalies.
The lymphatic-spread theory of Halban suggests that endometrial tissues are taken up into the lymphatics draining the uterus and are transported to the various pelvic sites where the tissue grows ectopically. Endometrial tissue has been found in pelvic lymphatics in up to 20% of patients with the disease .
The mullerian metaplasia theory of Meyer proposes that endometriosis results from the metaplastic transformation of peritoneal mesothelium into endometrium under the influence of certain unidentified stimuli.
The retrograde menstruation theory of Sampson proposes that endometrial fragments transported through the fallopian tubes at the time of menstruation implant and grow in various intra-abdominal sites. Endometrial tissue normally sheds at the time of menstruation is viable and capable of growth in vivo or in vitro.
To explain some rare examples of endometriosis in distant sites, such as the forehead or axilla, it is necessary to postulate hematogenous spread. Quite probably, all of these postulated mechanisms play a role in the development of endometriosis, and no single mechanism explains all cases.
Endometriosis occurs most commonly in the ovaries, the broad ligament, the peritoneal surfaces of the cul-de-sac including the uterosacral ligaments and posterior cervix, and in the rectovaginal septum (Fig. 1). Quite frequently, the rectosigmoid colon is involved, as is the appendix and the vesicouterine fold of the peritoneum. Endometriosis is occasionally seen in laparotomy scars, developing especially after cesarean sections or myomectomies when the endometrial cavity has been entered. In spite of the great variety of sites, 60% of patients with endometriosis have ovarian involvement.
Characteristically, an endometriosis of the ovary forms a small cyst. It is filled with thick, chocolate-colored fluid that sometimes has the black color and tarry consistency of crankcase oil. This characteristic fluid represents aged, hemolyzed blood and desquamated endometrium .
Usually, endometrial glands and stroma are present in the cyst wall. Sometimes, however, the pressure of the enclosed fluid destroys the endometrial lining of the endometrioma, leaving only a fibrotic cyst wall infiltrated with large numbers of hemosiderin-laden macrophages .
Most often, the ovarian endometrioma is tightly adherent to the posterior leaf of the broad ligament bound by adhesions. An ovarian endometrioma may reach dimensions as large as 20cm in diameter. Most instances of ovarian endometriosis are bilateral, and there is usually involvement of parietal and visceral peritoneal surfaces.
When endometriosis involves the peritoneal surfaces, it appears as flat, brownish discolorations, often referred to as “powder burns” or, if they are raised and bluish in color, as “mulberry spots.” The tissues surrounding these lesions are puckered and scarred as a result of fibrosis. Frequently, the rectosigmoid colon becomes tightly bound by dense endometriotic adhesions to the posterior wall of the lower uterine segment and cervix, resulting in fixed retroversion of the uterus and obliteration of the cul-de-sac.
The characteristic triad of symptoms associated with endometriosis is dysmenorrhea, dyspareunia, and dyschezia. Generally, secondary dysmenorrhea first appears or worsens in the late twenties or early thirties. If the endometriosis is associated with obstructive genital anomalies, severe dysmenorrhea may commence at menarche.
Dyspareunia is generally associated with deep penetration and occurs mainly when the cul-de-sac, uterosacral ligaments, and portions of the posterior vaginal fornix are involved. Endometriomata in these sites are usually exquisitely tender to touch.
Dyschezia is experienced with uterosacral, cul-de-sac, and rectosigmoid colon involvement. As the stool passes between the uterosacral ligaments, the characteristic dyschezia is experienced. This symptom is highly characteristic and is much more common with endometriosis than with chronic salpingo-oophoritis, a condition that is often confused with endometriosis.
Premenstrual and postmenstrual spotting is a characteristic symptom of endometriosis. Menorrhagia is uncommon, the amount of menstrual flow usually diminishing with endometriosis. If the ovarian capsule is involved with endometriosis, ovulatory pain and midcycle vaginal bleeding often become a problem. Rarely, as other organ systems are involved, menstrual hematochezia, hematuria, and other forms of vicarious menstruation become evident.
The nature of pelvic pain caused by endometriosis is variable. It has been stated that the degree of pain varies inversely with the extent of the disease. Minimal endometriosis in the cul-de-sac is generally much more painful than a huge endometrioma within the ovary that is expanding freely into the abdominal cavity.
Infertility as a symptom of endometriosis is difficult to understand completely and even more difficult to quantify. Although approximately 10% of “normal” couples are infertile, some 30% to 40% of couples are infertile if the female presents with endometriosis. The condition is found in 40% to 50% of women who undergo surgery for infertility.
Endometriosis presents with a wide variety of signs varying from the presence of a small, exquieitely tender nodule in the cul-de-sac or on the uterosacral ligaments to a huge, relatively nontender, cystic abdominal mass.
Occasionally, a small tender mulberry spot may be seen in the posterior fornix of the vagina. Characteristically, a tender, fixed adnexal mass is abserved on bimanual examination. The uterus is retroverted in a substantial number of women surgically explored for endometriosis. Frequently, no signs at all are abserved on physical examination. The characteristic sharp, firm, exquisitely tender “barb” felt in the uterosacral ligament is the diagnostic sine qua non of endometriosis.
The main differential diagnosis confused with endometriosis are (1) chronic pelvic inflammatory disease or recurrent acute salpingitis, (2) hemorrhagic corpus luteum, (3) benign or malignant ovarian neoplasm, and, occasionally, (4) ectopic pregnancy.
The diagnosis of endometriosis should be suspected in an afebrile patient with the characteristic symptom triad of endometriosis, a firm, fixed, tender adnexal mass, and tender nodularity in the cul-de-sac and uterosacral ligaments.
This diagnosis is even more likely if the leukocyte count and erythrocyte sedimentation rate are normal. The serum CA-125 level is frequently elevated. An ultrasonic evaluation may indicate an adnexal mass of complex echogenicity. The definitive diagnosis is generally made by the characteristic gross and histologic findings at laparoscopy or laparotomy.
The management of endometriosis depends on certain key considerations: (1) the certainty of the diagnosis, (2) the severity of the symptoms, (3) the extent of the disease, (4) the desire for future fertility, (5) the age of the patient, and (6) the threat to the gastrointestinal or urinary tracts or both.
If endometriosis is minimal in extent and the symptoms are tolerable, no treatment is necessary, but the patient should be observed at 6-month intervals. The use of
medroxyprogesterone acetate or a combined estrogen and progestin oral contraceptive on a cyclic basis may inhibit the growth of endometriosis, since this treatment effects an “exhaustion atrophy” of the normally placed or ectopic endometrium.
If the disease is minimal and symptoms are incapacitating or if infertility is a problem, the endometriosis may be treated by a pseudopregnancy regimen , using either escalating continuous doses of combined oral contraceptives or progestin only over a period of 6 to 9 months. Although most cases treated with pseudopregnancy result in temporary relief of symptoms and up to 40% may become pregnant following cessation of treatment, this regimen is poorly tolerated by most patients, and the endometriosis generally redevelops following cessation of treatment. Continuous progestin may be more effective than continuous oral contraceptives.
Danazol, an androgen dervative, may also be used in a “ pseudomenopause” regimen to suppress symptoms of endometriosis if fertility is not a present concern. It is given over a period of 6 to 9 months, and a dose of 100 to 800 mg daily may be necessary to suppress menstruation .
Endometriosis may be treated with a gonadotropin-releasing hormone (GnRH) agonist that effects a temporary medical castration, thereby bringing about a marked, albeit temporary, regression of endometriosis. Side effects of treatment and expense restrict longterm use. dose of 200 μg twice daily.
Mifepristone (RU 486), which is widely used as an abortifacient in Europe, is also used in the medical management of endometriosis. It is a synthetic analogue of progesterone with antiprogestational and anticorticoid activity. It binds directly with progesterone receptors .
Large (6 to 20 cm) endometriomata are amenable to surgical resection only. If the patient is older than 45years, the preferred treatment is a total abdominal hysterectomy (TAH) and bilateral salpingo-oophorectomy (BSO), even if the disease is entirely resectable.
If fertility is desired, conservative surgery must be considered, such as resection of endometriomas and lysis of tubal adhesions. Following the surgical resection of endometriosis, 50% to 60% of patients become pregnant, usually in the first 2 years following surgery. Even with minimal endometriosis, laparoscopic resection has been reported to significantly improve fertility rates.
It is generally accepted that about 15% of women develop varying degrees of adenomyosis in their late 30s and early 40s. Originally, adenomyosis was referred to as endometrosis interna, but these terms have become archaic. About 15 % of patients with adenomyosis have associated endometriosis. The basal layers of the endometrium extend in continuity to sites within the myometrium and generally do not participate in the proliferative and secretory cycles induced by the ovary.
Generally, the uterus grossly is diffusely enlarged with a thickened myometrium containing characteristic glandular irregularities (Fig. 2). The endometrial cavity is also enlarged, consistent with the increased myometrium.
Histologically, the extent of this process varies a great deal from superficial extension into the underlying myometrium, to extension throughout the myometrium, occasionally with penetration of the peritoneal surface of the uterus.
Occasionlly, the adenomyosis may be confined to one portion of the myometrium and take the form of a fairly well-circumscribed adenomyoma. Contrary to the picture in a uterine myoma, no distinct capsular margin can be detected on cut section between the adenomyoma and the surrounding myometrium.
Typical symptoms of adenomyosis are severe secondary dysmenorrhea and menorrheagia . The menorrhagia is consistent with the enlarged surface area of the endometrial cavity and the increased volume of sloughed endometrium.
The dysmenorrhea is of the colicky type. Many patients are asymptomatic. In about 30 to40 per cent of patients with adenomyosis, the disease is a surprise pathologic finding in a patient without menorrhagia, dysmenorrhea, or uterine enlargement. Occasionally, in a patient with a large adenomyoma, pressure on the bladder or rectum may create a problem.
On pelvic examination, the uterus is symmetrically enlarged. Occasionally, it may enlarge asymmetrically and make it impossible to distinguish this condition from that of a myomatous uterus. The consistency of the enlarged adenomyomatous uterus is generally softer than that of a uterine myoma. On rare occasions, endometrial cancer may arise in a focus of adenomyosis.
The treatment of adenomyosis depends entirely on the symptoms and the possibility of other diagnoses. Any menorrhagia in an older patient (>35 years) should be investigated by endometrial biopsy or fractional dilatation and curettage and/or hysteroscopy to rule out endometrial cancer.
If the menorrhagia is severe and recurrent following a dilatation and curettage or if the dysmenorrhea is disabling, the use of a GnRH agonist or mifepristone may provide relief. Total abdominal or vaginal hysterectomy, however, may be indicated. The ovaries should be preserved if they are normal, unless the patient is older than 45 years .
All of the following conditons have been implicated in the pathogenesis of endometriosis EXCEPT
A coelomic metaplasia
B endometrial hyperplasia
C retrograde menstruation
D immunologic deficiency
E lymphatic spread of endometrial fragment
Dyspareunia in endometriosis is associated with all of the following EXCEPT: