Ultrasound
Follow-up imaging in women of reproductive age for incidentally discovered simple cysts on ultrasound is not needed until 5 cm, as these are usually normal ovarian follicles. Simple cysts 5 to 7 cm in premenopausal females should be followed yearly. Simple cysts larger than 7 cm require further imaging with MRI or surgical assessment. Because they are large, they cannot be reliably assessed by ultrasound alone; it can be difficult to see posterior wall soft tissue nodularity or thickened septation due to limited ultrasound beam penetrance at this size and depth. For the corpus luteum, a dominant ovulating follicle that typically appears as a cyst with circumferentially thickened walls and crenulated inner margins, follow up is not needed if the cyst is less than 3 cm in diameter. In postmenopausal patients, any simple cyst greater than 1 cm but less than 7 cm needs yearly follow-up, while those greater than 7 cm need MRI or surgical evaluation, similar to reproductive age females. For incidentally discovered dermoids, diagnosed on ultrasound by their pathognomonic echogenic fat, either surgical removal or yearly follow up is indicated, regardless of patient age. For peritoneal inclusion cysts, which have a crumpled tissue-paper appearance and tend to follow the contour of adjacent organs, follow up is based on clinical history. Hydrosalpinx, or fallopian tube dilation, can be mistaken for an ovarian cyst due to its anechoic appearance. Follow-up for this is also based on clinical presentation.For multiloculate cysts with thin septation less than 3 mm, surgical evaluation is recommended.
The presence of multiloculation suggests a neoplasm, although the thin septation implies that the neoplasm is benign. For any thickened septation, nodularity, vascular flow on color doppler, or growth over several ultrasounds, surgical removal may be considered due to concern of cancer. Scoring systems
There are several systems to assess risk of an ovarian cyst of being an ovarian cancer, including the RMI (risk of malignancy index), LR2 and SR (simple rules). Sensitivities and specificities of these systems are given in tables below:
Ovarian cysts may be classified according to whether they are a variant of the normal menstrual cycle, referred to as a functional or follicular cyst.Ovarian cysts are considered large when they are over 5 cm and giant when they are over 15 cm. In children, ovarian cysts reaching above the level of the umbilicus are considered giant. Associated conditions
In juvenile hypothyroidism multicystic ovaries are present in about 75% of cases, while large ovarian cysts and elevated ovarian tumor marks are one of the symptoms of the Van Wyk and Grumbach syndrome.The CA-125 marker in children and adolescents can be frequently elevated even in absence of malignancy and conservative management should be considered.