Atlas of pathophysiology, 2 Edition

Part II - Disorders

Genital Diseases

Endometriosis

Endometriosis is the presence of endometrial tissue outside the lining of the uterine cavity. Ectopic tissue is generally confined to the pelvic area, usually around the ovaries, uterovesical peritoneum, uterosacral ligaments, and cul de sac, but it can appear anywhere in the body.

Active endometriosis may occur at any age, including adolescence. As many as 50% of infertile women may have endometriosis, although the true incidence in both fertile and infertile women remains unknown.

Severe symptoms of endometriosis may have an abrupt onset or may develop over many years. Of women with endometriosis, 30% to 40% become infertile. Endometriosis usually manifests during the menstrual years; after menopause, it tends to subside.

Causes

Primary cause unknown

Suggested causes (one or more may be true in different women)

·   Retrograde menstruation with implantation at ectopic sites; may not be causative alone; occurs in women with no clinical evidence of endometriosis

·   Genetic predisposition and depressed immune system

·   Coelomic metaplasia (metaplasia of mesothelial cells to the endometrial epithelium caused by repeated inflammation)

·   Lymphatic or hematogenous spread to extraperitoneal sites

Pathophysiology

The ectopic endometrial tissue responds to normal stimulation in the same way as the endometrium, but less predictably. The endometrial cells respond to estrogen and progesterone with proliferation and secretion. During menstruation, the ectopic tissue bleeds, which causes inflammation of the surrounding tissues. This inflammation causes fibrosis, leading to adhesions that produce pain and infertility.

Signs and symptoms

·   Classic symptoms—dysmenorrhea, abnormal uterine bleeding, infertility

·   Pain—begins 5 to 7 days before menses, peaks, and lasts for 2 to 3 days; severity doesn't reflect extent of disease

·   Depending on site of ectopic tissue:

§  ovaries and oviducts: infertility, profuse menses

§  ovaries or cul de sac: deep-thrust dyspareunia

§  bladder: suprapubic pain, dysuria, hematuria

§  large bowel, appendix: abdominal cramps, pain on defecation, constipation, bloody stools

§  cervix, vagina, perineum: bleeding from endometrial deposits, painful intercourse

Diagnostic test results

·   Laparoscopy or laparotomy reveal multiple tender nodules on uterosacral ligaments or in the rectovaginal septum, and ovarian enlargement in the presence of endometrial cysts on the ovaries.

·   A pelvic ultrasound test detects an endometrial tissue on an ovary.

·   Empiric trial of gonadotropin-releasing hormone (Gn-RH) agonist therapy confirms or refutes the impression of endometriosis before resorting to laparoscopy.

·   Biopsy at the time of laparoscopy may be helpful to confirm the diagnosis.

Treatment

Conservative therapy for young women who want to have children

·   Androgens such as danazol

·   Progestins and continuous combined oral contraceptives (pseudopregnancy regimen) to relieve symptoms by causing regression of endometrial tissue

·   Gn-RH agonists to induce pseudomenopause (medical oophorectomy), causing remission of the disease (commonly used)

·   Analgesics

·   Antigonadotropin drugs

To rule out cancer, when ovarian masses are present

·   Laparoscopic removal of endometrial implants

Treatment of last resort for women who don't want to bear children or with extensive disease

·   Total abdominal hysterectomy with or without bilateral salpingo-oophorectomy; success rates vary; unclear whether ovarian conservation is appropriate

P.317

PELVIC ENDOMETRIOSIS

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Clinical Tip: Common sites of endometriosis

Ectopic endometrial tissue can implant almost anywhere in the pelvic peritoneum. It can even invade distant sites such as the lungs.

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