Classification of ovarian tumors

Classification of tumor-like lesions

Retention cysts belong to the group of tumor-like lesions. They form due to the retention of excess fluid in pre-existing cavities—follicles, corpus luteum, epoophoron (parovarium), or foci of endometriosis implanted onto the ovarian surface.

The incidence rate is distributed as follows:

• Follicular — 73%
• Endometrioid — 10%
• Parovarian — 10%
• Corpus luteum cysts — 5%
• Theca lutein cysts — 2%

This pathology is most frequently detected in women of reproductive age against the background of dyshormonal processes, inflammation, or conditions causing pelvic congestive hyperemia. However, in 15% of cases, cysts are found in postmenopause and can occasionally even occur in newborns.

Follicular cyst: pathogenesis and morphology

A follicular cyst is the result of endocrine and metabolic disorders in which a follicle fails to ovulate and instead transforms into a cystic atretic lesion. This process is promoted by hyperestrogenism and chronic anovulation (monophasic cycle). Fluid accumulates inside due to transudation from blood vessels or continued secretion by the granulosa epithelium.

Macroscopically, this is a smooth, thin-walled lesion 50–60 mm in diameter with light yellow, transparent contents. The wall is initially lined with several layers of follicular epithelium and externally covered by fibrous tissue. As the cyst stretches, the epithelium undergoes degeneration, thins, and desquamates. Eventually, the capsule may consist solely of connective tissue. Such formations are usually unilocular, but with the simultaneous growth and fusion of several cysts, they may present a false appearance of multilocularity.

Clinical presentation and complications

In most cases, uncomplicated cysts are asymptomatic. Patients occasionally report delayed menstruation and lower abdominal pain of varying intensity, which usually appears during the active formation of the cavity.

Complications that present with the clinical picture of an "acute abdomen" (severe pain, nausea, vomiting) pose a health threat:

1. Torsion of the cyst pedicle — causes impaired venous outflow, tissue edema, hemorrhage into the wall, and a rapid increase in the size of the lesion.
2. Rupture of the wall.
3. Hemorrhage into the cyst cavity.

Diagnostics

The diagnosis is established comprehensively based on clinical findings, ultrasound, and laparoscopy.

During gynecological palpation lateral or anterior to the uterus, an elastic, rounded, mobile, and mildly tender mass measuring 5–6 cm is identified. It is usually unilateral (bilateral cysts typically indicate ovarian hyperstimulation during infertility treatment).

Ultrasound criteria (echogram):

• Anechoic contents with high sound transmission.
• Thin, regular wall (up to 2 mm).
• Diameter ranging from 2.5 to 6 cm.
• Specific sign: acoustic enhancement effect posterior to the lesion.
• In women of active reproductive age, a section of intact ovarian tissue is often visualized nearby.

On color Doppler mapping (CDM), blood flow is detected exclusively at the periphery, characterized by low velocity and moderate resistance (Resistance Index $\ge$ 0.4). Dynamic ultrasound is necessary for differential diagnosis with a smooth-walled serous cystadenoma.

Management and treatment

Uncomplicated forms require active surveillance for 6–8 weeks. The patient is prescribed anti-inflammatory therapy or (strictly according to indications) hormone therapy. Follicular cysts tend to undergo spontaneous regression, which usually occurs within 1–2 (less frequently 3) menstrual cycles.

If conservative management is ineffective or complications arise, surgical intervention is indicated. The method of choice is laparoscopy. In reproductive age, cyst enucleation is performed with maximum preservation of healthy ovarian tissue. In perimenopause, removal of the uterine appendages (salpingo-oophorectomy) on the affected side is indicated.

To normalize menstrual function in the postoperative period, the following are prescribed for 3 months:

• Cyclic vitamin therapy (folic acid, vitamins C and E).
• Nootropic drugs (piracetam).
• Contraceptives (to suppress ovulation and prevent recurrence).

Overall, the prognosis for this condition is favorable.

Class and exam questions

What else to study on this topic

• Endometrioid and parovarian cysts: sources of origin
• Corpus luteum cysts and theca lutein cysts
• Differential diagnosis of cysts and smooth-walled serous cystadenoma
• Technique of laparoscopic ovarian cyst enucleation
• Hormone therapy regimens for retention lesions

Other topics in the "Gynecology" section

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