Most women of reproductive age develop small cysts each month, and large cysts that cause problems occur in about 8% of women before menopause. Ovarian cysts are present in about 16% of women after menopause and if present are more likely to be cancer.

Benign ovarian cysts are common in asymptomatic premenarchal girls and found in approximately 68% of ovaries of girls 2–12 years old and in 84% of ovaries of girls 0–2 years old. Most of them are smaller than 9 mm while about 10-20% are larger macrocysts. While the smaller cysts mostly disappear within 6 months the larger ones appear to be more persistent.

A malignant mixed Müllerian tumor, also known as malignant mixed mesodermal tumor, MMMT and carcinosarcoma, is a malignant neoplasm found in the uterus, the ovaries, the fallopian tubes and other parts of the body that contains both carcinomatous (epithelial tissue) and sarcomatous (connective tissue) components. It is divided into two types, homologous (in which the sarcomatous component is made of tissues found in the uterus such as endometrial, fibrous and/or smooth muscle tissues) and a heterologous type (made up of tissues not found in the uterus, such as cartilage, skeletal muscle and/or bone). MMMT account for between two and five percent of all tumors derived from the body of the uterus, and are found predominantly in postmenopausal women with an average age of 66 years. Risk factors are similar to those of adenocarcinomas and include obesity, exogenous estrogen therapies, and nulliparity. Less well-understood but potential risk factors include tamoxifen therapy and pelvic irradiation.

Ovarian torsion accounts for about 3% of gynecologic emergencies. The incidence of ovarian torsion among women of all ages is 5.9 per 100,000 women, and the incidence among women of reproductive age (15–45 years) is 9.9 per 100,000 women. In 70% of cases, it is diagnosed in women between 20 and 39 years of age. The risk is greater during pregnancy and in menopause. Risk factors include increased length of the ovarian ligaments, pathologically enlarged ovaries (more than 6 cm), ovarian masses or cysts, and enlarged corpus luteum in pregnancy.

Cysts associated with hypothyroidism or other endocrine problems are managed by treating the underlying condition.

About 95% of ovarian cysts are benign, not cancerous.

Functional cysts and hemorrhagic ovarian cysts usually resolve spontaneously. However, the bigger an ovarian cyst is, the less likely it is to disappear on its own. Treatment may be required if cysts persist over several months, grow, or cause increasing pain.

Cysts that persist beyond two or three menstrual cycles, or occur in post-menopausal women, may indicate more serious disease and should be investigated through ultrasonography and laparoscopy, especially in cases where family members have had ovarian cancer. Such cysts may require surgical biopsy. Additionally, a blood test may be taken before surgery to check for elevated CA-125, a tumour marker, which is often found in increased levels in ovarian cancer, although it can also be elevated by other conditions resulting in a large number of false positives.

Ovarian pregnancies are rare: the vast majority of ectopic pregnancies occur in the fallopian tube; only about 0.15-3% of ectopics occur in the ovary. The incidence has been reported to be about 1:3,000 to 1:7,000 deliveries.

There is debate over the naming of MMMT; the term carcinosarcoma was formerly used to describe lesions with homologous tumors, and "malignant mixed Müllerian tumor" or "mixed mesodermal tumor" was used to describe heterologous tumors. While "carcinosarcoma" now considered standard, "malignant mixed Müllerian tumor" has a lengthy history within gynecological literature and is expected to continue to be used. The naming issue to a certain extent reflects histological characteristics and development of the tumors, in which the different types of tissues are believed to either develop separately and join into a single mass (the "collision" theory), that an adenocarcinoma stimulates the stroma to create a tumor (the "composition" theory), or that the tumor is the result of a stem cell that differentiates into different cell types (the "combination" theory). "Collision" tumors are normally easily recognized and not considered true MMMTs; the "combination" theory is most widely held, and is due to evidence that the tumors develop from a single line of cells, developing in a fashion similar to the fundus of the uterus from the Müllerian duct - first from a stem cell into a population of cells, that then differentiates into epithelial and stromal components.

There is evidence that some tumors are better explained by the composition theory, due to the aggressive nature of the epithelial cells involved which tend to metastasize much more readily than the sarcomal component. The behavior of MMMT overall is more related to the type and grade of the epithelium than the sarcoma, which suggests the sarcomal portion is an atypical "bystander" than primary driver of the tumor. Despite this, when purely endometrial tumors are compared to MMMTs, the MMMT tumor tends to have a worse prognosis.

In premenopausal women, adnexal masses include ovarian cysts, ectopic (tubal) pregnancies, benign (noncancerous) or malignant (cancerous) tumors, endometriomas, polycystic ovaries, and tubo-ovarian abscess. In females of reproductive age, adnexal masses can be physiologic or complex masses. Most common causes for adnexal masses in premenopausal women are follicular cysts and corpus luteum cysts. Abscesses can form as a complication of pelvic inflammatory disease.

Other masses include endometriomas, polycystic ovaries, and benign neoplasms.

In postmenopausal women, adnexal masses may be caused by cancer, fibroids, fibromas, diverticular abscess.

An adnexal mass is a lump in tissue of the adnexa of uterus (structures closely related structurally and functionally to the uterus such as the ovaries, fallopian tubes, or any of the surrounding connective tissue). Adnexal masses can be benign or cancerous, and they can be categorized as simple or complex. One of the most important factors used to determine the clinical suspicion of malignancy of an adnexal mass is the sonographic appearance of the mass. Indications that the mass is at a higher risk of being malignant include: presence of loculations, nodules, papillary structures, septations, size greater than 10 cm.

A 2006 review stated that RS often leads renal cancer between ages 30-50. Renal cancer kills about 1 in 3 people, but 5-year survival rates improved between 1974-1976 and 1995-2000, from 52% to 64%.

The fertility drug clomiphene citrate (Clomid, Serophene), used to induce ovulation, increases the risk of a corpus luteum cyst developing after ovulation. These cysts don't prevent or threaten a resulting pregnancy. Women on birth control pills usually do not form these cysts; in fact, preventing these cysts is one way birth control pills work.

In contrast, the progesterone-only pill can cause increased frequency of these cysts.

True cervical pregnancies tend to abort; if, however, the pregnancy is located higher in the canal and the placenta finds support in the uterine cavity it can go past the first trimester. With the placenta being implanted abnormally extensive vaginal bleeding can be expected at time of delivery and placental removal. While early cervical pregnancies may abort spontaneously or can be managed with excision, D&C, suturing, electrocautery, and tamponading, by medication such as methotrexate, and/or by uterine artery embolization, a more advanced pregnancy may require a hysterectomy to control bleeding. The more advanced the pregnancy the higher the risk for a major bleeding necessitating a hysterectomy.

On a very rare occasion, a cervical pregnancy results in the birth of a live baby, typically the pregnancy is in the upper part of the cervical canal and manages to extend into the lower part of the uterine cavity.

A cervical pregnancy can develop together with a normal intrauterine pregnancy; such a heterotopic pregnancy will call for expert management as to not to endanger the intrauterine pregnancy.

Lipomatosis is believed to be a hereditary condition in which multiple lipomas are present on the body.

Adiposis dolorosa (Dercum disease) is a rare condition involving multiple painful lipomas, swelling, and fatigue. Early studies mentioned prevalence in obese postmenopausal women. However, current literature demonstrates that Dercum disease is present in more women than men of all body types; the average age for diagnosis is 35 years.

Benign symmetric lipomatosis (Madelung disease) is another condition involving lipomatosis. It nearly always appears in middle-aged males after many years of alcoholism. But, non-alcoholics and females can also be affected.

Other relatively rare conditions have been reported in association with this disease. It is not yet known if these associations are fortuitous or manifestations of the condition itself.

Cerebral cavernomas and massive, macronodular adrenocortical disease have also been reported in association with this syndrome. A case of cutis verticis gyrata, disseminated collagenoma and Charcot-Marie-Tooth disease in association with a mutation in the fumarate hydratase gene has also been reported. Two cases of ovarian mucinous cystadenoma have also been reported with this mutation.

Ovarian pregnancies are dangerous and prone to internal bleeding. Thus, when suspected, intervention is called for.

Traditionally, an explorative laparotomy was performed, and once the ovarian pregnancy was identified, an oophorectomy or salpingo-oophorectomy was performed, including the removal of the pregnancy. Today, the surgery can often be performed via laparoscopy. The extent of surgery varies according to the amount of tissue destruction that has

occurred. Patients with an ovarian pregnancy have a good prognosis for future fertility and therefore conservative surgical management is advocated. Further, in attempts to preserve ovarian tissue, surgery may involve just the removal of the pregnancy with only a part of the ovary. This can be accomplished by an ovarian wedge resection.

Ovarian pregnancies have been successfully treated with methotrexate since it was introduced in the management of ectopic pregnancy in 1988.

An ovarian pregnancy can develop together with a normal intrauterine pregnancy; such a heterotopic pregnancy will call for expert management as not to endanger the intrauterine pregnancy.

The tendency to develop a lipoma is not necessarily hereditary, although hereditary conditions such as familial multiple lipomatosis might include lipoma development. Genetic studies in mice have shown a correlation between the "HMG I-C" gene (previously identified as a gene related to obesity) and lipoma development. These studies support prior epidemiologic data in humans showing a correlation between "HMG I-C" and mesenchymal tumors.

Cases have been reported where minor injuries are alleged to have triggered the growth of a lipoma, called "post-traumatic lipomas." However, the link between trauma and the development of lipomas is controversial.

The development of an ovarian mass is related to the development of torsion. In the reproductive years, regular growth of large corpus luteal cysts are a risk factor for rotation. The mass effect of ovarian tumors is also a common cause of torsion. Torsion of the ovary usually occurs with torsion of the fallopian tube as well on their shared vascular pedicle around the broad ligament, although in rare cases the ovary rotates around the mesovarium or the fallopian tube rotates around the mesosalpinx. In 80%, torsion happens unilaterally, with slight predominance on the right.

The prevalence of heterotopic pregnancy is estimated at 0.6‑2.5:10,000 pregnancies. There is a significant increase in the incidence of heterotopic pregnancy in women undergoing ovulation induction. An even greater incidence of heterotopic pregnancy is reported in pregnancies following assisted reproduction techniques such as In Vitro Fertilization (IVF) and Gamete intrafallopian transfer (GIFT), with an estimated incidence at between 1 and 3 in 100 pregnancies. If there is embryo transfer of more than 4 embryos, the risk has been quoted as 1 in 45. In natural conceptions, the incidence of heterotopic pregnancy has been estimated to be 1 in 30 000 pregnancies.

A Corpus luteum cyst is a type of ovarian cyst which may rupture about the time of menstruation, and take up to three months to disappear entirely. A corpus luteum cyst rarely occurs at age 50+, because eggs are no longer being released in menopausal women. Corpus luteum cysts may contain blood and other fluids. The physical shape of a corpus luteum cyst may appear as an enlargement of the ovary itself, rather than a distinct mass -like growth on the surface of the ovary.

Extrauterine pregnancies are non-viable and can be fatal to the mother if left untreated. The mortality rate for the extrauterine pregnancy is approximately 35%.

The incidence has been reported to be about 1:1,000 to 1: 16,000 pregnancies.

Pregnancies involving the isthmus - the segment of the uterus between the cervix and the fundus - are more common than true cervical pregnancies. While in many situations the cause of the abnormal implantation remains unclear, there is evidence to link the development of cervical pregnancy to uterine instrumentation, specifically repeated D&Cs (dilatation and curettage). Cervical pregnancies are to be distinguished from pregnancies that start from an implantation in a scar of a previous cesarean section, so-called "scar pregnancies".

Ovarian apoplexy is a sudden rupture in the ovary, commonly at the site of a cyst, accompanied by hemorrhage in the ovarian tissue and/or intraperitoneal bleeding.

Treatment depends on the type of ovary apoplexy and the severity of intra-abdominal bleeding, but the condition must be treated in a hospital. In the case of pain without signs of intraabdominal bleeding, conservative therapy may be initiated, which includes bed rest, antispasmodics, and physiotherapy. In the presence or suspected internal bleeding, surgery is indicated via laparoscopy or laparotomy. Other treatments may include efforts to stop the bleeding or resection of the affected portion of the ovary. However, in cases in which there is extensive damage to the ovary, it may be necessary to remove it.

After being discharged from the hospital, it is important to take steps to prevent a recurrence in the future. Such steps include avoiding risk factors or beginning a regimen of oral contraceptives to control ovarian activity.

10% of cases occur in women who are ovulating, but progesterone secretion is prolonged because estrogen levels are low. This causes irregular shedding of the uterine lining and break-through bleeding. Some evidence has associated Ovulatory DUB with more fragile blood vessels in the uterus.

It may represent a possible endocrine dysfunction, resulting in menorrhagia or metrorrhagia.

Mid-cycle bleeding may indicate a transient estrogen decline, while late-cycle bleeding may indicate progesterone deficiency.

Dysfunctional uterine bleeding (DUB) is abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable structural or organic disease. It is usually due to hormonal disturbances: reduced levels of progesterone cause low levels of prostaglandin F2alpha and cause menorrhagia (abnormally heavy flow); increased levels of tissue plasminogen activator (TPA) (a fibrinolytic enzyme) lead to more fibrinolysis.

Diagnosis must be made by exclusion, since organic pathology must first be ruled out.

DUB can be classified as "ovulatory" or "anovulatory", depending on whether ovulation is occurring or not. It is usually a menstrual disorder, although abnormal bleeding from the uterus is possible outside menstruation.

Some sources state that the term "dysfunctional" implies a hormonal mechanism. Use of the term "abnormal uterine bleeding" is preferred in today's medicine.

There are various explanations, none of which is universally accepted because of the complex involvement of cortical, hypothalamic, endocrine, and psychogenic factors. Proposed mechanisms include the effect of stress on the hypothalamo-pituitary-adrenal axis, constipation, weight gain, and the movement of intestinal gas.