Benign ovarian tumors

Benign ovarian tumors are primarily functional cysts and tumors; most are asymptomatic.

Functional cysts develop from Graafian follicles (follicular cysts) or from the corpus luteum (corpus luteum cysts). Most functional cysts are less than 1.5 cm in diameter; a few exceed 8 cm, and very rarely reach 15 cm. Functional cysts usually resolve spontaneously within a few days to weeks. Bleeding may occur in corpus luteum cysts, which, by stretching the ovarian capsule, may lead to ovarian ruptures.

Benign ovarian tumors are usually slow growing and rarely undergo malignant transformation. The most common benign ovarian tumors are benign teratomas. These tumors are also called dermoid cysts because they arise from all three germ layer layers and are composed primarily of ectodermal tissue. Fibromas, the most common solid benign ovarian tumors, are slow growing and less than 7 cm in diameter. Cystadenomas may be serous or mucinous.

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Symptoms of benign ovarian tumors

Most functional cysts and benign tumors are asymptomatic. Hemorrhagic corpus luteum cysts may cause pain or signs of peritonitis. Sometimes there is very severe abdominal pain with torsion of the uterine appendages or ovarian cysts larger than 4 cm. Tumors are often discovered by chance, but they can also be suspected if symptoms are present. A pregnancy test should be performed to rule out ectopic pregnancy.

Types of benign ovarian tumors

The most common are epithelial tumors, dermoid cysts (mature teratomas), and ovarian fibromas. Benign ovarian tumors (except hormone-producing ones), regardless of their structure, have much in common in their clinical manifestations. In the early stages, the disease is usually asymptomatic.

Epithelial ovarian tumors

These tumors account for 75% of all ovarian neoplasms. Cilioepithelial and pseudomucinous cystadenomas of the ovaries develop from the Müllerian epithelium.

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Cilioepithelial tumors (serous)

There are two types of serous cystadenomas: smooth-walled and papillary. The inner surface of smooth-walled serous tumors is lined with ciliated epithelium. This cystadenoma is a thin-walled formation of spherical or ovoid shape with a smooth shiny surface, multi-chambered or more often single-chambered. The tumor rarely reaches very large sizes, contains a light transparent liquid.

Papillary tumors are divided by morphological structure into coarse papillary cystadenomas, superficial papillomas, and adenofibromas. A distinction is made between everting tumors, when the papillae are located only on the outer surface of the capsule; inverting tumors - only on the inner surface of the capsule; mixed tumors - when the papillae are located on both the inner and outer surfaces of the tumor capsule, and the tumor has a "cauliflower" appearance.

Features of the clinical course of papillary cystadenomas: bilateral ovarian involvement, intraligamentary location of tumors, ascites, papillae growth on the surface of the tumor and peritoneum, adhesions in the abdominal cavity, menstrual dysfunction and decreased reproductive function are common. The disease is more severe in the presence of an everting form and a bilateral process. Malignant transformation occurs in these tumors much more often than in others.

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Pseudomucinous cystomas

The tumor has an ovoid or spherical shape, often with an uneven lobular (due to bulging individual chambers) outer surface. The tumor capsule is smooth, shiny, silvery-white or bluish in color. Depending on the nature of the contents (admixture of blood, cholesterol, etc.) and the thickness of the walls, the tumor can have a variety of colors - from greenish-yellow to brown. In most cases, the tumor reaches significant sizes. Smooth-walled mucinous cystomas rarely affect both ovaries and have a well-defined pedicle. Interligamentous location of the tumor is rare. Adhesions with adjacent organs are not extensive. Torsion of the pedicle of a smooth-walled mucinous cystadenoma occurs in 20% of cases. Ascites in benign mucinous tumors is observed in 10% of patients.

Papillary mucinous ovarian tumors, unlike papillary serous tumors, always have a well-defined stalk. These cystadenomas are often accompanied by ascites, and they are also distinguished by a pronounced tendency to proliferate.

Hormone-producing ovarian tumors

Hormonally active ovarian tumors (5% of all tumors) are neoplasms originating from hormonally active structures of the "female" and "male" parts of the gonad, secreting estrogens or androgens, respectively. Feminizing and virilizing ovarian tumors are distinguished.

Feminizing tumors:

• Granulosa cell tumors – develop from granulosa cells of atretic follicles. Their frequency is 2-3% of the number of benign tumors. About 30% of granulosa cell tumors do not have hormonal activity, in 10% of tumors malignant transformation is possible. They most often occur in postmenopause, less than 5% of tumors are detected in childhood.

Histologically, micro-, macrofollicular, trabecular and sarcomatous types of granulosa cell tumors are distinguished, the latter being malignant.

• Theca cell tumors are formed from theca cells of the ovaries, their frequency is about 1% of all tumors. Tumors are detected more often in postmenopausal age. They are small in size. Tumors are solid in structure, dense, bright yellow in section. They are not prone to malignancy.

Features of clinical manifestations of feminizing ovarian tumors:

• in childhood, symptoms of precocious puberty;
• in reproductive age – menstrual dysfunction such as acyclic uterine bleeding, infertility;
• during menopause – disappearance of age-related atrophy of the external and internal genitalia, uterine bleeding, increased levels of estrogen hormones in the blood.

Feminizing tumors are characterized by slow growth.

Virilizing tumors:

• Androblastoma – occurs more often in women aged 20–40; its frequency is 0.2% among all tumors. The tumor is formed from the male part of the gonad and consists of Leydig and Sertoli cells.
• Arrhenoblastoma is a tumor of dystopic adrenal cortex tissue; its frequency is 1.5–2%. Malignant growth is observed in 20–25% of cases. The tumor is more common in young women – under 30 years of age; it has a dense capsule, small size, and often follows the shape of the ovary.
• Lipoid cell - consists of lipid-containing cells, belonging to the cell types of the adrenal cortex, and cells resembling Leydig cells. The tumor is the rarest among virilizing neoplasms and mainly occurs in the climacteric period and postmenopause.

Symptoms of virilizing tumors:

With the appearance of a virilizing tumor in a woman, defeminization (amenorrhea, atrophy of the mammary glands, decreased libido) first occurs, and then masculinization (growth of a mustache and beard, baldness, deepening of the voice).

Stromatogenic, or connective tissue, tumors

The frequency of these tumors among all ovarian tumors is 2.5%.

Ovarian fibroma is a tumor of the stromal sex cord, a group of thecoma fibromas. It arises from connective tissue. The tumor has a round or ovoid shape, often repeating the shape of the ovary. The consistency is dense. It occurs mainly in old age, grows slowly.

Clinically characteristic is the Meigs triad:

1. ovarian tumor;
2. ascites;
3. hydrothorax.

Brenner's tumor is a rare formation. It consists of epithelial elements located in the form of inclusions of various shapes among the connective tissue of the ovary.

Teratoid, or germ cell, ovarian tumors

Of the benign tumors of this group (10%), the most common is mature teratoma (dermoid), which has an ectodermal origin and is highly differentiated. The tumor can be of different sizes, has a dense smooth capsule, contents in the form of fat, hair, teeth, etc.

Other tumors of this group (teratoblastoma and dysgerminoma) are classified as malignant tumors.

Treatment of benign ovarian tumors

Most ovarian cysts smaller than 8 cm resolve without treatment; however, serial ultrasonographic studies are needed to confirm resolution of the cysts.

Cyst removal (ovarian cystectomy) is performed in the presence of cysts larger than 8 cm that persist for more than three menstrual cycles. Hemorrhagic corpus luteum cysts are removed in the presence of peritonitis. Cystectomy can be performed by laparoscopy or laparotomy. Cystectomy is necessary for cystic teratomas. Benign ovarian tumors such as fibroma, cystic adenoma, cystic teratoma larger than 10 cm, and cysts that cannot be surgically removed separately from the ovary are indications for ovary removal.