An adnexal mass is a growth that develops in the female pelvic region, usually in the ovaries, fallopian tubes, or connecting tissues. Adnexal masses can be benign or malignant, and they can originate from either the reproductive system or nearby pelvic organs, such as the intestines or the urinary bladder. Adnexal masses can occur in women of all ages, from childhood to senility, but they most commonly occur during the childbearing years.

The most common causes of adnexal masses in premenopausal women include ovarian cysts, ectopic (tubal) pregnancies, benign or malignant tumors, endometriomas, polycystic ovaries, and tubo-ovarian abscess. In postmenopausal women, adnexal masses may be caused by cancer, fibroids, fibromas, or diverticular abscesses.

Symptoms associated with adnexal masses include irregular vaginal bleeding, bloating, increased abdominal girth, dyspareunia, urinary symptoms, pelvic pain, and abdominal pain. However, many adnexal masses are asymptomatic and are discovered incidentally during a routine pelvic exam or imaging test.

Diagnosis of adnexal masses involves a careful physical exam, imaging tests, and sometimes surgery. One of the most important factors used to determine the clinical suspicion of malignancy of an adnexal mass is the sonographic (ultrasound) appearance of the mass. Indications that the mass is at a higher risk of being malignant include the presence of loculations, nodules, papillary structures, septations, or a size greater than 10 cm.

Treatment of adnexal masses depends on the underlying cause and the patients age and reproductive status. Removal of an adnexal mass is sometimes referred to as "adnexectomy". In many cases, adnexal masses aren’t harmful and will eventually resolve on their own. However, if they cause uncomfortable symptoms, then surgical removal may be recommended.