Page created on June 5, 2021. Last updated on May 27, 2022 at 13:51
Definition and epidemiology
An adnexal mass is a mass of the ovary, fallopian tube, or the surrounding connective tissue. Benign adnexal masses are common, and most of them are ovarian cysts. However, adnexal masses may be malignant and so it’s important to evaluate them to determine whether it is benign or malignant.
The patient may present with gynaecological symptoms like pelvic pain or pressure, or the mass may be incidentally discovered during imaging.
The following conditions can form adnexal masses:
- Ovarian cysts
- Benign ovarian tumours
- Ectopic pregnancy
- Ovarian cancer
- Fallopian tube cancer
- Metastasis from stomach, breast
Only the benign ones will be discussed here.
Evaluation and diagnosis
As always, history and physical examination is important. Patients should be asked about symptoms of malignancy, like changes in urination, abdominal distension, early satiety, pelvic pain, etc.
The first choice for imaging is ultrasound, usually transvaginal but also transabdominal. MRI or CT may also be used, but they’re not necessarily better than ultrasound.
Ultrasound features which suggest malignancy include large size (> 10 cm), solid masses, nodular masses, and thick septations. Features which suggest benignity include anechoic unilocular fluid-filled cysts with thin walls.
CA125 is a tumour marker for ovarian tumours. Its specificity is low in premenopausal but high in postmenopausal. It should be routinely measured in postmenopausal women with adnexal masses, and, if elevated, should raise suspicion of malignancy.
If imaging can’t rule out a malignancy, surgical exploration is performed to make a definitive diagnosis. Adnexal masses can’t be biopsied because it could cause cancer dissemination if it is malignant, so the adnexal mass must be removed by hysterectomy with bilateral salpingo-oophorectomy.
There are many types of ovarian cysts. The most common are the functional cysts and corpus luteal cyst. Their benignity can usually be determined on ultrasound.
Functional or physiological cysts are formed when the Graafian follicle does not rupture but continue to grow. They are common in young women and are smooth, thin walled, and unilocular on ultrasound.
Corpus luteal cysts, also called a lutein cysts, are formed when fluid builds in the corpus luteum. There are two types, granulosa lutein cysts and theca lutein cysts. They’re associated with progesterone-only contraceptive pills and fertility drugs like clomiphene. They have thicker walls and may contain haemorrhage.
Functional and corpus luteal cysts are generally asymptomatic and spontaneously resolve within a few weeks. If they rupture, become haemorrhagic, or torsion occurs, they may cause acute pain.
Benign ovarian tumours
Benign ovarian tumours may originate from ovarian surface epithelium, germ cells, or sex cord-stromal cells. The most common benign ovarian tumours are mature teratoma (dermoid cyst), serous cystadenoma, and mucinous cystadenoma. Other types include:
- Brenner cell tumours
- Sex cord stromal tumours
It is often difficult to differentiate benign ovarian tumours from malignant based on imaging. In uncertain cases, it’s better to be safe than sorry, so the ovaries should be removed surgically (bilateral salpingo-oophorectomy with hysterectomy) and examined histologically.