Benign tumours of the ovary

CHAPTER 44 Benign tumours of the ovary







Clinical Presentation of Symptomatic Ovarian Cysts


Benign ovarian cysts present as follows:










Investigation


The investigations required will depend upon the circumstances of the presentation. The patient presenting with acute symptoms will usually require emergency surgery, whereas the asymptomatic patient or the woman with chronic problems may benefit from more detailed preliminary assessment.









Ultrasound


The techniques of transabdominal and transvaginal ultrasound are discussed in detail in Chapter 6. Ultrasound is the single most important investigation and can demonstrate the presence of an ovarian mass with 81% sensitivity and 75% specificity. Most ovarian masses are cystic, whilst the presence of solid areas makes a malignancy more likely. Reporting of an ultrasound finding of an ovarian cyst has been standardized in order to allow for the allocation of a scoring system to assist in the preoperative assessment of the risk of any ovarian cyst being malignant. The ultrasound is awarded a U score of 0 if no cyst is present, 1 if only one characteristic is found, and 3 if two or more characteristics are found:







Computed tomography (CT) scanning has no significant advantages over ultrasound in cyst assessment, but can be useful in the presence of obvious extrapelvic disease to assess tumour bulk prior to chemotherapy. Magnetic resonance imaging (MRI) has a marginal advantage over CT in determining if a cyst is more likely to be benign or malignant, but both have no benefit over good transvaginal ultrasound and should not be used routinely. Initial studies using colour flow Doppler were promising but, once again, its use has not been proven to improve cyst assessment.



Risk of malignancy index


There is good evidence that primary surgery undertaken by a gynaecological oncologist improves survival in ovarian cancer by allowing for adequate staging and optimal debulking. It is not practical for all cysts to be managed by gynaecological oncologists; thus, in order to triage cysts for the appropriate surgeon, the Royal College of Obstetricians and Gynaecologists (RCOG) recommend use of the risk of malignancy index (RMI). In order to calculate the RMI, the menopausal status is also taken into account, with premenopausal being awarded a score of 1 and postmenopausal being awarded a score of 3. This simple formula is used:



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A score below 25 can be managed by any gynaecologist, a score of 25–250 should be managed by a cancer unit lead, and a score above 250 should be referred to a cancer centre. This assessment allows for 70% of ovarian cancers to be managed in a cancer centre. The specificity is 90%. The cysts most likely to result in confusion regarding their benign or malignant nature are endometriomas. The clinical history and examination may better inform the clinician but, as a general principle, a significantly raised CA125 (>300 u/ml) is almost always associated with malignant disease.


The Scottish Collegiate also uses an RMI scoring system but gives different weightings to the ultrasound findings and menopausal status. If there are two or more abnormal ultrasound features, they award a U score of 4, whilst a postmenopausal status also has a score of 4. In addition, referral to a cancer centre is recommended when the RMI score is above 200. These adaptations increase the sensitivity of the RMI for prediction of malignant disease from 70% to 80%, and increase the specificity from 89% to 92%. Many centres in the UK also apply this RMI.


Jun 4, 2016 | Posted by in GYNECOLOGY | Comments Off on Benign tumours of the ovary

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