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Review: Lesions of the Ovary and Fallopian Tube

Key findings

  • Lesions of the adnexa (ovary or fallopian tube) are common and span a wide differential diagnosis with a spectrum of benign to malignant causes
  • Key goals of management are to quickly recognize a surgical emergency, have a high suspicion for the presence of malignancy, and refer to an appropriate specialist as required
  • Ultrasound is the most important study for assessing an adnexal lesion, but there is no universally accepted system for radiologic classification of benign, malignant, and borderline masses
  • Simple, unilocular lesions can be managed with observation; complex lesions that are likely benign can be managed with observation or surgery. Complex lesions that are concerning for malignancy should be referred to gynecologic oncology
  • All patients with high-risk adnexal lesions should be referred to a gynecologic oncologist for evaluation and treatment

Lesions of the ovary and fallopian tube (together, the adnexa) are common throughout the life cycle and have many causes, from benign to malignant.

In The New England Journal of Medicine, Rachel C. Sisodia, MD, and Marcela G. del Carmen, MD, MPH, gynecologic oncologists in the Center for Gynecologic Oncology at the Mass General Cancer Center, recently reviewed the anatomy and physiology, evaluation and diagnosis, and management of adnexal lesions, including in children and pregnant women. This summary focuses on the evaluation of adults and indications for referral.

Rule Out Acute Conditions

The initial and most crucial step in evaluating adnexal lesions is to ascertain the need for immediate surgery. Patients with hemodynamic instability, peritonitis, or evidence of bowel or urinary obstruction should be assessed in the emergency department. Patients of reproductive age should be tested immediately for human chorionic gonadotropin to rule out ectopic pregnancy and the potential for fatal hemoperitoneum.

Assess the Need for Intervention

Further evaluation should assess the risk of malignancy and the likelihood a benign process would benefit from management by a specialist. A detailed table in the review provides the differential diagnosis for an adnexal lesion based on its appearance on imaging.

Biopsy should almost always be avoided, as it can result in intra-abdominal spillage of tumor cells and subsequent upstaging of cancer.

History—Older age is the greatest independent risk factor for adnexal cancer. Family history is another critical component of the history-taking, as 20% of ovarian and tubal cancers are due to a heritable gene mutation.

Physical examination—A comprehensive examination includes a pelvic examination, but its sensitivity for detecting an adnexal mass is low, and it cannot reliably differentiate between benign and malignant masses. It is most important for informing surgical planning.

Imaging—Transvaginal ultrasound should be the initial radiologic test because of its performance characteristics, safety profile, and cost-effectiveness. However, there is no universally accepted classification system for adnexal lesions.

Tables in the paper describe the International Ovarian Tumor Analysis (IOTA) simple rules, based on data from high-volume centers, and the Ovarian–Adnexal Reporting and Data System. The latter is new, published in 2020, but initial validation data suggest it is highly reliable.

MRI is a useful adjunct for evaluating masses described as indeterminate but should not be the first-line study. CT is the best choice for staging known ovarian cancer but performs poorly in an initial assessment of an adnexal mass.

Laboratory testing—Women of reproductive age should be screened for pregnancy if there is concern about the possibility of ectopic pregnancy, gestational trophoblastic neoplasia, or pregnancy concurrent with an adnexal mass. A complete blood count helps guide the management of women suspected of having a tubo-ovarian abscess or ovarian torsion.

The most important laboratory studies are serum tumor marker tests: human epididymis protein 4, which is FDA-approved for determining the likelihood that an ovarian mass is cancerous, and CA-125, approved for monitoring the response to ovarian cancer treatment but frequently used off-label to help categorize adnexal masses.

CA-125 level is not elevated in all cases of ovarian cancer, though, and it is elevated in many nononcologic conditions. CA-125 testing alone is not diagnostic of epithelial ovarian cancer.

Indications for Referral

Simple unilocular cysts, common in women of all ages, are invariably benign and often resolve spontaneously. Thin septations do not increase the risk of cancer. The 2016 American College of Obstetricians and Gynecologists (ACOG) guidelines recommend considering one year of follow-up for stable cysts without solid components and up to two years for stable, low-risk lesions with solid components.

Complex lesions—Hemorrhagic cysts, endometriomas, and mature teratomas are all benign. Referral to a gynecologic surgeon should be considered, although asymptomatic patients are generally offered observation. Women who wish to conceive should be referred to an infertility specialist.

Indeterminate or malignant lesions—The 2016 ACOG guidelines recommend consultation with a gynecologic oncologist for women with an adnexal mass who are:

  • Postmenopausal with a CA-125 level ≥35 U/mL; ultrasound findings suggestive of cancer, ascites, or a nodular or fixed pelvic mass; or evidence of abdominal or distant metastasis
  • Premenopausal with a "very elevated" CA-125 level (not defined); ultrasound findings suggestive of cancer, ascites, or a nodular or fixed pelvic mass; or evidence of abdominal or distant metastasis
  • Premenopausal or postmenopausal with an elevated score on a formal risk assessment test (e.g., the commercial Overa or OVA1 test, or the Risk of Malignancy Algorithm, an online calculator) or one of the IOTA scoring systems

Multiple studies have shown that for women with high-risk adnexal lesions, comprehensive surgical staging and tumor debulking are associated with increased survival.

Learn more about the Center for Gynecologic Oncology

Refer a patient to the Center for Gynecologic Oncology


Researchers in the Center for Gynecologic Oncology found that among patients at high genetic risk of ovarian cancer who undergo prophylactic surgery, health-related worry and tension decline post-operatively, but sexual dysfunction and short-term quality of life are poorer.


In this video, Rachel Sisodia, MD, discusses how incorporating patient voice into their care via patient-reported outcomes can improve their care journey and health outcomes.