Ovarian Pathology
The most common types of lesions encountered in the ovary include functional or benign cysts and tumors. Intrinsic inflammations of the ovary (oophoritis) are uncommon, usually accompanying tubal inflammation. Rarely, a primary inflammatory disorder involving ovarian follicles (autoimmune oophoritis) occurs and is associated with infertility.
Non-Neoplastic and Functional Cysts
FOLLICULAR AND LUTEAL CYSTS
Cystic follicles in the ovary are so common as to be virtually physiologic. They originate in unruptured graafian follicles or in follicles that have ruptured and immediately sealed.
Morphology.
These cysts are usually multiple. They range in size up to 2 cm in diameter, are filled with a clear serous fluid, and are lined by a gray, glistening membrane. On occasion, larger cysts exceeding 2 cm (follicular cysts) may be diagnosed by palpation or ultrasonography and cause pelvic pain.
Granulosa lining cells can be identified histologically if the intraluminal pressure has not been too great. The outer theca cells may be conspicuous with increased cytoplasm and a pale appearance (luteinized). As discussed subsequently, when this alteration is pronounced (hyperthecosis), it may ultimately result in increased estrogen production and endometrial abnormalities.
Morphology:
Macroscopically:
The ovaries are usually twice normal size, gray-white with a smooth outer cortex, and are studded with subcortical cysts 0.5 to 1.5 cm in diameter.
Microscopic examination:
there is a thickened superficial cortex beneath which are innumerable follicle cysts with hyperplasia of the theca interna (follicular hyperthecosis) Corpora lutea are frequently but not invariably absent.
Pathogenesis of PCOD:
The initiating event in polycystic ovarian disease is not clear.
Increased secretion of luteinizing hormone may stimulate the theca-lutein cells of the follicles, with excessive production of androgen (androstenedione), which is converted to estrone.
For years, these endocrine abnormalities were attributed to primary ovarian dysfunction because large wedge resections of the ovaries sometimes restored fertility.
It is now believed that a variety of enzymes involved in androgen biosynthesis are poorly regulated in polycystic ovarian disease. Recent studies link polycystic ovarian disease, like type II diabetes, to insulin resistance. Administration of insulin mediators has been associated with resumption of ovulation.
Theca lutein hyperplasia of pregnancy.
In response to pregnancy hormones (gonadotropins), proliferation of theca cells with expansion of the perifollicular zone occurs.
As the follicles regress, the concentric theca-lutein hyperplasia may appear nodular. This change is not to be confused with true luteomas of pregnancy.
Ovarian Tumors
Tumors of the ovary are common forms of neoplasia in women.
Among cancers of the female genital tract, the incidence of ovarian cancer ranks below only carcinoma of the cervix and the endometrium.
Ovarian cancer accounts for 6% of all cancers in the female , because many of these ovarian neoplasms cannot be detected early in their development, they account for a disproportionate number of fatal cancers, being responsible for almost half of the deaths from cancer of the female genital tract. There are numerous types of ovarian tumors, both benign and malignant. About 80% are benign, and these occur mostly in young women between the ages of 20 and 45 years. The malignant tumors are more common in older women between the ages of 40 and 65 years.Pathogenesis:
Risk factors for ovarian cancer are much less clear than for other genital tumors, but nulliparity, family history, and heritable mutations play a role in tumor development.
There is a higher frequency of carcinoma in unmarried women and in married women with low parity.
Gonadal dysgenesis in children is associated with a higher risk of ovarian cancer.
Women 40 to 59 years of age who have taken oral contraceptives or undergone tubal ligation have a reduced risk of developing ovarian cancer.
The most intriguing risk factors are genetic.
mutations in both BRCA1 and BRCA2 increase susceptibility to ovarian cancer BRCA1 mutations occur in about 5% of patients younger than 70 years of age with ovarian cancer. The estimated risk of ovarian cancer in women bearing BRCA1 or BRCA2 mutations is 20% to 60% by the age of 70 years.
Most of these cancers are serous cystadenocarcinomas.
Approximately 30% of ovarian adenocarcinomas express high levels of HER2/neu (ERB-B2) oncogene, which correlates with a poor prognosis.
Mutations in the tumor-suppressor gene p53 are found in 50% of ovarian carcinomas.
Classification.
The classification of ovarian tumors given in is a simplified version of the World Health Organization Histological Classification, which separates ovarian neoplasms according to the most probable tissue of origin. There is, as usual, a group of tumors that defy classification, and finally there are secondary or metastatic tumors, the ovary being a common site of metastases from a variety of other cancers.
Classification of Ovarian Tumor
It is now believed that tumors of the ovary arise ultimately from one of three ovarian components: (1) surface epithelium derived from either the coelomic epithelium or ectopic endometrial epithelium (see endometriosis, later). The former gives rise to the müllerian epithelium during embryonic development. From it are derived the fallopian tubes (ciliated columnar serous cells), the endometrial lining (nonciliated, columnar cells), or the endocervical glands (mucinous nonciliated cells); (2) the germ cells, which migrate to the ovary from the yolk sac and are totipotential; and (3) the stroma of the ovary, which includes the sex cords, forerunners of the endocrine apparatus of the postnatal ovary.
Cl. Features:
Although some of the specific tumors have distinctive features and are hormonally active, most are nonfunctional and tend to produce relatively mild symptoms until they have reached a large size.
Malignant tumors have usually spread outside the ovary by the time a definitive diagnosis is made. Some of these tumors, principally epithelial tumors, tend to be bilateral. lists these tumors and their subtypes and shows the frequency of bilateral occurrence. Abdominal pain and distention, urinary and gastrointestinal tract symptoms due to compression by tumor or cancer invasion, and abdominal and vaginal bleeding are the most common symptoms. The benign forms may be entirely asymptomatic and occasionally are unexpected findings on abdominal or pelvic examination or during surgery.