Definition
Ovarian cysts are formations that develop on the surface or within the parenchyma of the ovary. In most cases an ovarian cyst represents a benign condition and may be completely asymptomatic, often identified incidentally during a routine gynecologic examination. In some circumstances, however, it is necessary to rule out malignant nature and assess for associated complications such as ovarian torsion, hemorrhage, or cyst rupture.
From a clinical standpoint, two main categories are distinguished:
- Functional cysts: follicular cysts, corpus luteum cysts, and theca-lutein cysts
- Pathological and non-functional cysts: cystadenomas, dermoid cysts, endometriotic cysts, and polycystic ovaries
Functional cysts
Functional cysts represent the most frequent type and affect approximately 20% of women of reproductive age. They develop in relation to the physiologic mechanisms of ovulation. During the ovarian cycle, under hormonal stimulation, the ovary produces a fluid-filled structure called a follicle, within which the oocyte is contained. At the time of ovulation, the follicle ruptures, allowing the release of the oocyte into the fallopian tube where fertilization may occur.
Follicular cysts
Follicular cysts develop when the follicle does not rupture during ovulation. They appear as round formations, single or multiple, with variable dimensions generally between 3 and 10 cm, characterized by thin walls and translucent fluid content. In most cases they cause no symptoms; occasionally they may produce estrogens, leading to menstrual cycle alterations such as irregular bleeding, heavier or lighter periods, sometimes painful.
Corpus luteum cysts
Corpus luteum cysts are also frequent in women of reproductive age. They form following ovulation and may derive from a hematoma of the corpus luteum, the residual structure of the follicle after oocyte release. They may remain asymptomatic or, in relation to progesterone production, cause reduced menstrual flow or short duration and, in some cases, reproductive difficulties.
Theca-lutein cysts
Theca-lutein cysts generally develop under conditions of marked ovarian stimulation. They may be observed during pregnancy or in women undergoing assisted reproduction treatments.
Functional cysts are benign formations whose characteristics may vary during the different phases of the menstrual cycle. In the majority of cases they cause no symptoms and tend to regress spontaneously after menstruation or after medical treatment with combined estrogen-progestogen therapy. Surgical treatment is considered in the presence of large cysts, with risk of complications such as hemorrhage, rupture, or ovarian torsion, or in case of symptoms related to compression of adjacent organs.
Pathological cysts
Pathological cysts represent ovarian formations that require clinical workup and, in many cases, surgical treatment.
Dermoid cysts
Mature teratomas originate from embryonic germ cells and may contain differentiated tissues such as bone structures, hair, teeth, or adipose tissue. Surgical intervention is indicated both to rule out possible malignant transformation and because of the tendency to dimensional growth, which may reach approximately 15 cm.
Cystadenomas
These are benign formations containing serous fluid (serous cystadenomas) or mucinous material (mucinous cystadenomas). In these cases as well, accurate workup is necessary to rule out borderline or malignant forms.
Endometriotic cysts
These develop when endometrial tissue and endometrial stroma localize outside the uterine cavity, involving the ovary. Although the risk of malignant transformation is generally low, it is higher in women with endometrioma.
Polycystic ovaries
This is an endocrine condition characterized by the presence of enlarged ovaries with numerous small cysts. It is a disorder linked to hormonal imbalance with androgen excess, requiring a distinct diagnostic and therapeutic approach compared to isolated ovarian cysts.
Diagnosis
The reference examination for the initial evaluation of ovarian cysts is transvaginal ultrasound. This examination allows an initial distinction between functional cysts, benign cysts, and suspicious lesions through analysis of various parameters: laterality, size, mass composition (cystic, solid, or mixed), presence of internal septa, papillary projections or mural nodules, free fluid in the pelvic cavity, and assessment of vascularization with color Doppler.
Ultrasound findings consistent with a benign lesion include thin and regular walls, absence of septa or solid components, and absence of internal vascular flow on color Doppler.
Several elements should raise suspicion of malignancy and prompt further investigation: size greater than 10 cm, complex multilocular masses, presence of papillary projections or solid components, irregular walls, thick septa, ascites, and increased vascularization on color Doppler.
In selected cases CT or MRI imaging is performed, along with measurement of tumor markers such as CA-125, HE4, and others depending on the clinical context. In women of reproductive age a pregnancy test is always appropriate.
Treatment
Treatment of ovarian cysts depends on several clinical factors, including patient age, presence of symptoms, and risk of malignancy. In women of reproductive age, when ultrasound shows benign features compatible with a functional cyst, ultrasound follow-up after 3–4 weeks is generally indicated, as approximately 60% of lesions regress spontaneously. Alternatively, combined estrogen-progestogen therapy may be prescribed for a period of 3–4 months.
In the presence of suspicious cysts, lack of regression after medical therapy, or in postmenopausal patients, surgical evaluation by laparoscopy is performed. This is a minimally invasive technique that allows visualization of the abdominal cavity and adnexa with a camera and surgical instruments introduced through small skin incisions. This procedure allows both treatment of the lesion and intraoperative histologic evaluation to rule out malignancy.
The type of intervention varies according to patient age:
- In women of reproductive age, cystectomy is generally performed, that is, removal of the cyst alone preserving ovarian tissue
- In postmenopausal women, adnexectomy is more frequently performed, namely removal of the ovary and tube, unilateral or bilateral depending on clinical indications
Frequently asked questions
Ovarian cysts are frequently asymptomatic and are often identified incidentally during ultrasound performed for other reasons. When symptomatic, the most common complaints include pelvic or abdominal pain localized to one side, sense of pelvic pressure or fullness, and abdominal distension.
Other possible symptoms include pain during sexual intercourse, menstrual irregularities, and increased urinary frequency. In cases of ovarian torsion, nausea and vomiting are associated. Sudden onset of severe abdominal pain requires urgent clinical evaluation as it may indicate cyst rupture or ovarian torsion.
Ref.: [1, 2, 3, 4]
In most cases yes. Simple ovarian cysts resolve spontaneously in 50–70% of cases. Functional cysts, such as follicular or corpus luteum cysts, tend to disappear within 6–12 weeks without any treatment.
Prospective follow-up studies have demonstrated that more than two-thirds of unilocular cysts in postmenopausal women may regress spontaneously over time. Smaller cysts tend to resolve more rapidly than larger ones.
Ref.: [5, 6, 7]
An ovarian cyst becomes clinically relevant when it causes acute complications or shows features suspicious for malignancy. The main warning signs are: size greater than 10 cm, presence of solid or papillary components, sudden severe abdominal pain (possible ovarian torsion), hemodynamic instability suggesting hemorrhage, presence of ascites, and irregular cyst wall.
Ovarian torsion represents one of the main gynecologic emergencies and typically presents with sudden abdominal pain associated with nausea and vomiting. The risk increases in the presence of cysts larger than 5 cm.
Ref.: [1, 2, 8, 9]
An ovarian cyst is a single benign lesion of the ovary, generally fluid-filled and often destined to spontaneous regression.
Polycystic ovary syndrome (PCOS) is instead a complex endocrine disorder requiring the presence of at least two of the three Rotterdam criteria: clinical or biochemical hyperandrogenism, oligomenorrhea or amenorrhea, and polycystic ovarian morphology on ultrasound. PCOS is associated with menstrual irregularities, hirsutism, acne, infertility, and increased metabolic risk. The occasional presence of multiple cysts on ultrasound is not sufficient on its own to diagnose PCOS.
Ref.: [10, 11, 12]
Simple ovarian cysts generally do not compromise fertility. However, certain types, particularly endometriomas, may affect ovarian reserve, leading to reduced anti-Müllerian hormone (AMH) levels and antral follicle count.
In some cases, surgery to remove the cyst may have a greater impact on ovarian reserve than the cyst itself. In patients desiring pregnancy who present with endometriomas, specialist workup is often appropriate before considering surgical intervention.
Ref.: [13, 14]
Ovarian cyst rupture is generally a self-limiting event that may cause acute pain. In most cases (approximately 84.7%) management is conservative with clinical observation and analgesic therapy.
Surgical intervention is considered only in the presence of hemodynamic instability, large amounts of free abdominal fluid, large cysts, or persistent pain despite medical therapy. Hemorrhagic ruptures of the corpus luteum represent the most frequent form and tend to resolve spontaneously.
Ref.: [8, 9]
Surgical intervention is indicated in the following cases: suspected malignancy based on ultrasound findings or tumor markers, presence of persistent or severe symptoms, cysts that do not regress after an adequate period of observation, large cysts (greater than 10 cm), acute complications such as torsion or rupture with hemorrhage, persistent complex ovarian masses.
Simple cysts up to 10 cm may be monitored with ultrasound follow-up even in postmenopausal women.
Ref.: [5, 6]
Laparoscopy is a minimally invasive surgical technique involving small skin incisions, generally 5–10 mm, through which a camera and surgical instruments are introduced. For benign ovarian cysts, this technique allows: reduction of postoperative pain, shorter hospital stay, faster functional recovery, and reduction of perioperative complications.
During the procedure, Prof. Di Donato may perform a cystectomy, that is, removal of the cyst preserving the ovary, or more rarely an oophorectomy. In women of reproductive age, fertility preservation represents a priority objective.
Ref.: [6]
Scientific evidence indicates that oral contraceptives do not accelerate the resolution of already-existing functional cysts. A Cochrane review of randomized trials demonstrated that most cysts resolve spontaneously within 4–6 weeks regardless of pill use.
Oral contraceptives may however be useful in preventing the formation of new functional cysts, as they suppress ovulation.
Ref.: [15, 16, 17]
Diagnostic evaluation of ovarian cysts is primarily based on ultrasound imaging and selected laboratory tests. Transvaginal ultrasound is the first-choice examination to assess size, morphology, and vascularization of the lesion. In selected cases CT or MRI is added, especially when malignancy is suspected.
Laboratory tests include the pregnancy test (beta-hCG) in women of reproductive age, CA-125 (particularly useful in postmenopause), complete blood count in case of suspected torsion or infection, and other tumor markers such as HE4 and alpha-fetoprotein in selected cases.
Ref.: [1, 5, 6]
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