Endometriosis is a prevalent benign illness defined by the presence of endometrial glands and stroma outside of the uterine cavity, primarily on the ovary, pelvic peritoneum, and rectovaginal septum [1]. It is linked to infertility and a variety of problems, including chronic pelvic pain, dysmenorrhea, deep dyspareunia, dysuria, dyschezia, and fatigue [2,3]. However, symptom severity is not usually proportional to the endometriosis stage, and some women with endometriosis may be asymptomatic.

Traditionally, endometriosis has been diagnosed through diagnostic laparoscopy or the histological identification of lesions. However, with recent developments in imaging modalities, the necessity for diagnostic laparoscopy in cases where endometriosis is relatively obvious has been questioned, and concerns have been raised regarding delays in the endometriosis diagnosis due to the diagnostic laparoscopic and histological confirmation criteria.

In 2022, the new European Society of Human Reproduction and Embryology (ESHRE) guidelines were published [4]. Although the new guidelines are not perfect, they provide clearer guidance on many difficult issues, such as medication selection among combined oral contraceptives (COCs), progestogen, and gonadotropin-releasing hormone (GnRH) agonists, and surgical indications for endometrioma in patients preparing for pregnancy.

The ESHRE guidelines are one of the most frequently cited endometriosis-related guidelines. It is believed that referring to representative changes in the new guidelines and major updates will be beneficial for diagnosing and treating endometriosis (Table 1). This paper provides a brief overview of these developments.

The previous ESHRE guidelines suggested that laparoscopic histologic confirmation of endometriosis was the gold standard for an endometriosis diagnosis. In contrast, according to the new ESHRE guidelines, laparoscopy is no longer the diagnostic gold standard and is now only advised for patients with negative imaging results and/or when empirical treatment is ineffective or unsuitable. This change was based on a meta-analysis regarding endometriosis diagnostic tools. According to a Cochrane review, imaging modalities such as transvaginal ultrasonography and magnetic resonance imaging showed sensitivity and specificity for diagnosing endometrioma and deep endometriosis comparable to a surgical diagnosis (Table 2) [5]. As an added explanation in the new guidelines, the difficulties and limitations of making a noninvasive diagnosis of a superficial disease are described. Despite these limitations, stating that diagnostic laparoscopy is not the gold standard emphasizes the usefulness of imaging modalities for diagnosing endometrioma and deep endometriosis.

Discomfort related to endometriosis includes dysmenorrhea, dyspareunia, dysuria, dyschezia, and non-menstrual pelvic pain. In prior Korean and international guidelines, the hormonal medical treatment for endometriosis-associated pain has consisted of COCs, progestogens, anti-progestogens, aromatase inhibitors, and danazol. However, in the new guidelines, GnRH antagonists were introduced as a second treatment option, while anti-progestogens and danazol were withdrawn.

The recurrence rate of endometriosis has been reported to range from 0% to 89.6% [17]. This variation could be related to differences in the definitions of recurrence, length of follow-up, study design, sample size, type and stage of disease, type of operation, and postoperative medical care [17]. As the high recurrence rate and its significance have been consistently emphasized, they are described in a separate chapter, unlike in the earlier guidelines. For preventing recurrence, ovarian cystectomy instead of drainage/electrocoagulation and postoperative hormonal treatment for at least 18 to 24 months are recommended. The recommended duration of hormonal treatment is based on RCTs. However, in patients who are not immediately seeking conception, long-term hormonal therapy is recommended.

There are scarce data on endometriosis and adolescence. Although there are no major differences between the diagnosis and treatment of endometriosis in adolescents and adults, clinicians treating adolescents should be vigilant regarding several factors. Not only is dysmenorrhea a major symptom of endometriosis, but it is also a highly prevalent occurrence in adolescents, and it takes significantly longer to reach a diagnosis of endometriosis in adolescents than in adults. When previous treatments have failed, clinicians may consider prescribing a GnRH agonist for up to 1 year. If GnRH agonist treatment is considered for young women and adolescents, it should be delivered only after careful evaluation and a discussion of potential adverse effects and long-term health problems with a practitioner in a secondary or tertiary care setting, as recommended by the GDG. As with adults, no studies have addressed the efficacy or utility of fertility preservation—specifically, oocyte cryopreservation—in adolescents with endometriosis. Although the true benefits, safety, and indications for adolescents with endometriosis remain unknown, the GDG recommends informing adolescents about fertility preservation options.

The amount of data available regarding the prevalence of endometriosis after menopause is extremely limited. A recent retrospective cohort study described a 4% prevalence of postmenopausal endometriosis [18]. It is hypothesized that menopausal hormone therapy can increase the formation of endometriosis [19] and a variety of factors, some of which are unknown, can also affect the growth of endometriosis. Therefore, it is important for clinicians to be aware that endometriosis might continue to be active and cause symptoms after menopause.

For postmenopausal women presenting with signs of endometriosis and/or discomfort, clinicians might consider surgical treatment as a means of enabling histological confirmation of the diagnosis of endometriosis. The GDG suggests that practitioners emphasize the ambiguity regarding the risk of cancer in postmenopausal women. If a mass is found in the pelvis, a diagnostic workup and treatment should be carried out in accordance with the national oncology standards. Clinicians may consider aromatase inhibitors as a potential therapeutic option for endometriosis-related pain in postmenopausal women, particularly if surgery is not a viable option.

Clinicians should be aware that women with endometriosis who undergo early bilateral salpingo-oophorectomy as part of their therapy have a higher risk of decreased bone density, dementia, and cardiovascular disease. It is also essential to emphasize that women with endometriosis have a higher risk of cardiovascular disease, regardless of whether they have undergone early surgical menopause.

For the management of postmenopausal symptoms in women with a history of endometriosis, combined menopausal hormone therapy may be considered; however, tibolone is no longer recommended as a medical treatment for menopausal symptoms in women with a history of endometriosis.

Clinicians should be aware of the symptoms of extra-pelvic endometriosis, which include cyclical shoulder discomfort, cyclical spontaneous pneumothorax, cyclical cough, and enlargement of nodules during menstruation. The diagnosis and treatment of extra-pelvic endometriosis should be discussed by a multidisciplinary team at an institution with sufficient expertise. When possible, surgical excision is the best treatment for alleviating symptoms in women with abdominal extra-pelvic endometriosis. If surgery is inapplicable or unacceptable, hormonal therapy may also be an alternative.

Clinicians should not regularly perform surgical excision/ablation for asymptomatic endometriosis discovered incidentally during surgery. Practitioners should not suggest medical therapy to women with an incidental endometriosis diagnosis, but routine ultrasound surveillance must be recommended. Even in the absence of convincing data on the benefits of monitoring asymptomatic endometriosis, the GDG recommends considering ultrasound surveillance due to its low cost and safety.

The objective of primary prevention is to prevent healthy and asymptomatic women from developing endometriosis. Although there is no direct proof of the efficacy of a healthy lifestyle and diet in preventing endometriosis, women can be counseled to adopt a healthy lifestyle and diet, including reduced alcohol use and regular physical activity. The efficacy of hormonal contraceptives for the primary prevention of endometriosis is uncertain. Genetic testing of women with suspected or proven endometriosis should only be undertaken in a research context, citing the newly added text.

According to the 2014 recommendations, ovarian cancer and non-Hodgkin lymphoma were slightly prevalent among endometriosis patients. Nevertheless, according to a recent systematic review and meta-analysis of 49 cohort or case-control studies, endometriosis was related to a very slight and not statistically significant higher risk of cancer overall (summary relative risk [SRR], 1.07; 95% confidence interval [CI], 0.96–1.16) [20]. Endometriosis was related to an increased risk of ovarian cancer (SRR, 1.93), especially clear-cell (SRR, 3.44) and endometrioid (SRR, 2.33) histotypes, breast cancer (SRR, 1.04) and thyroid cancer (SRR, 1.39) [20]. Although endometriosis is associated with an elevated risk of certain cancers, given the low absolute risks of ovarian, breast, and thyroid cancer in people with endometriosis relative to those without (increases of 1.2%p, 0.5%p, and 0.5%p, respectively) and the uncertainty regarding the risk of other cancers, endometriosis patients can be reassured that their cancer risk is low and comparable to that of people without the disease. Clinicians should educate women with endometriosis who request information on their cancer risk that endometriosis is not associated with an increased risk of cancer. Although endometriosis is related to a somewhat higher risk of ovarian, breast, and thyroid malignancies, the absolute increase in risk relative to the general female population is minimal (Table 3).

The new ESHRE recommendations are clearer and more practical than their predecessors and other guidelines. However, as stated on the opening page of the ESHRE guidelines, clinical practice guidelines do not supersede the clinical decisions made by a healthcare professional for diagnosis and treatment. Ultimately, healthcare professionals must make their own clinical decisions case by case, with consideration of various circumstances.