Endometriosis is the presence of endometrial glands and stroma outside of the endometrial cavity. The presence of endometriosis in adolescents is well documented, however the exact prevalence in adolescents is unknown. The prevalence in menstruating women is reported anywhere from 1 to 17%.

The etiology of endometriosis remains unclear. Attempts to explain the pathophysiology of endometriosis have included Sampson’s theory of retrograde menstrual flow, the coelomic metaplasia theory which suggests that estrogen stimulation transforms coelomic epithelium into endometrial-type glands, as well as genetic and immunologic factors.

Adolescents with endometriosis typically present with pelvic pain. Patients will typically report worsening symptoms at or near the time of their menses, but they may experience acyclic pain as well. Most adolescents with endometriosis have normal physical findings on examination. Abnormal physical findings may include tenderness on pelvic examination but would rarely include significant masses or nodularity more commonly seen in adults. Patients with dysmenorrhea or CPP unresponsive to NSAIDS and OCPs should be evaluated for endometriosis. The incidence of endometriosis in this population is reported to be as high as 70%. Endometriosis should also be considered in patients with a family history of endometriosis since 6.9% of first-degree relatives of patients with endometriosis have the disease.

Diagnostic laparoscopy is required to confirm the diagnosis of endometriosis. Endometriosis in adolescents usually presents at an earlier stage (stage I or II) than in the adult patient and presents with more of the atypical endometriotic implants, which are clear, white, or red in appearance.

Early and accurate diagnosis of endometriosis is important in adolescents not only for symptom relief but also to halt the progression of the disease and to preserve fertility.

There is no cure for endometriosis short of a hysterectomy, therefore in the adolescent, treatment is usually conservative in nature with a combination of medical and surgical interventions. Surgical intervention usually begins with diagnostic laparoscopy where all grossly visible lesions are coagulated, resected, or ablated. If indicated other conservative surgical measures include lysis of adhesions with restoration of normal pelvic anatomy. After the primary surgical intervention for diagnosis and conservative treatment, medical therapy is initiated to suppress endometrial glands and stroma to limit the progression of disease. Commonly used medical therapies include OCPs, progestins, danazol, and GnRH analogs.

OCPs and depot medroxyprogesterone acetate both offer suppression of endometriosis as well as contraception for the sexually active adolescent. Some clinicians advocate use of continuous OCPs, omitting the placebo week for patients with endometriosis.

Danazol can be very effective for symptom relief, however, it is often poorly tolerated by patients because of the unwanted side effects of acne and weight gain.

GnRH analogs have proven efficacy in the adult population for treatment of endometriosis. Add-back therapy in the form of progestin with or without estrogen has been shown useful in the adult population to minimize the hot flashes and bone mineral density loss noted with the GnRH analogs. GnRH analogs should not be used for longer than 6 months, and there are concerns with using them in younger adolescents with regard to bone mineral density loss.