Location and function of the ovaries

The ovaries are female reproductive organs located in the pelvic cavity. They lie below the fallopian tubes, one on each side of the uterus.

Ovaries are oval-shaped the size of an almond. Within each ovary, there are multiple follicles containing oocyte (ovum) or female reproductive cells in the outer zone of the ovary or ‘cortex’. Each month a follicle grows and releases an ovum around the mid-period of the menstrual cycle. The ovum is then transported to the fallopian tube where fertilization by a sperm may occur. The fertilized egg then migrates to the uterus, implants in the proliferating endometrium, and continues to develop as a fetus. If there is no sperm or fertilization, the ovum shrinks, and the endometrium will slough off and shed as menses. The ovaries also secrete female hormones including estrogen and progesterone.

Ovarian cysts

An ovarian cyst is a fluid-filled sac that can be found inside or on the surface of the ovaries. Generally, ovarian cysts can be classified into 3 major types.

1. Type 1: Functional cyst, a result of the normal functioning of the ovaries. A functional cyst usually has the following features.
   • being small (with a diameter not larger than 8 cm).
   • having no solid part.
   • having no or minimal symptoms.
   • spontaneously develops and shrinks during each menstrual cycle (or within 2-3 months)
   • no treatment required

Common types of functional cysts include:

• Follicular cyst Physiologically, a follicle bursts and releases an ovum midway through a menstrual cycle. If a follicle does not rupture, it will keep growing into a follicular cyst.
• Corpus luteum cyst After an ovum is released, the follicle transforms into a corpus luteum (of yellow color and possibly with blood inside).  Without fertilization, the corpus luteum will shrivel up within about 10 days.

2. Type 2: A cyst or mass lesions from pathologic conditions such as endometriomas (commonly known as chocolate cyst) due to aberrant (ectopic) growth of endometrial tissues in the ovaries; or tubo-ovarian abscess, which is the inflammation of fallopian tubes and ovaries with collection of pus.
3. Type 3: A cyst or mass which can be either benign or malignant in nature.
   • Benign or non-cancerous tumor. An example of a common tumor in this category is a dermoid tumor or benign teratoma, which contains a mixture of tissues including hair, teeth, or skin producing fat, or serous or mucinous tumor which originates from the surface epithelial lining of the ovaries.
   • Malignant or cancerous tumor. Mass in this category generally has both cystic and solid components or may be completely solid. Examples are serous or mucinous cystadenocarcinoma.

Type 2 and 3 ovarian cysts/masses are pathologic lesions requiring treatment; otherwise, they could endanger the health of the affected woman or even cost a life, especially when there are leakages, rupture, invasion, or metastases to other organs.

Risk factors

The risk factors for ovarian cysts are:

• Chronic anovulation which can lead to the accumulation of cystic content or many follicles
• Use of stimulating hormone rendering an increase of follicles
• Endometriosis with progressive pathological change resulting in collection of blood appearing as chocolate cyst
• Chronic or severe pelvic infection leading to a collection of purulent materials or abscess of ovaries and/or fallopian tubes
• History of an ovarian cyst
• Family history of ovarian cancer, breast cancer, or other related types of cancers

Symptoms

Small ovarian cysts usually are asymptomatic. However, large cysts can cause the following:

1. Symptoms due to mass or pressure effect of the lump
   • Poor appetite or early satiety
   • Abdominal bloating, dyspepsia, nausea, and vomiting
   • Ascites (collection of fluid in the abdomen), abdominal fullness, and palpable lump
   • Frequent urination, diarrhea, or chronic constipation
2. Systemic symptoms such as unexplained weight loss or weight gain, etc.
3. Symptoms secondary to the spread of cancer such as coughing, jaundice, etc.
4. Symptoms due to complications of the cyst/mass:
   • Fever, nausea, vomiting, and pelvic pain from ovarian torsion which blocks or cuts off blood flow to the ovaries, leading to dead tissue and/or bleeding.
   • Severe pain or shock (fatigue, dizziness, and cold hands and feet) due to cyst rupture with internal abdominal bleeding. The risk of rupture is higher with a large tumor after blunt abdominal trauma or strenuous exercise.

Prevention

Risk of ovarian cysts can be minimized but not eliminated. Always notice if you have any unusual changes in your body or symptoms. Seeing your doctor for an annual checkup or pelvic exam can help detect abnormalities sooner. Physical examinations including special imaging study can help identify even small, asymptomatic cyst. Consult your gynecologist if you have any chronic, persistent, serious, or acute symptoms in your pelvis or any other symptoms with unknown cause.

Diagnosis

Your doctor will gather all information by inquiring about your menstruation, medical condition, medications, dietary, or herbal supplements, as well as your family history.  

If you have any symptoms, your doctor will ask in detail about its onset, severity, relation to menstruation, and things (e.g., activity, position, drug, etc.) that improve or aggravate your condition.

After collecting all information, the doctor will proceed to a physical examination, pelvic exam, and other appropriate diagnostic investigations.

Diagnostic modalities, for example, are:

1. Imaging study. Transvaginal ultrasound is usually the first diagnostic imaging used by a gynecologist. Other imaging studies may include, but are not limited to CT scan, or MRI. Imaging will help determine the location, size, and type of an ovarian cyst, to check whether it is a fluid-filled sac, solid, or cystic-solid mass. Other pelvic structures including the uterus will be assessed for abnormalities as well
2. Pregnancy test. It may be obtained if indicated by history and/or physical examination for women of reproductive age.
3. Blood test for tumor markers. The most common is CA125, which often increases in patients with ovarian cancer. However, the level of CA125 can be high due to other conditions e.g., the latter phase of the menstrual cycle, pregnancy, pelvic inflammatory disease, endometriosis, uterine fibroid, tumors, or cancers of other organs. The doctor will take the CA125 level and other clinical findings into consideration for assessment of the ovarian cyst/mass.
4. Laparoscopy This is a minimally invasive surgical procedure for the evaluation, diagnosis, and treatment by removal of ovarian cysts in the same setting.

Treatment

Your gynecologist will counsel you about the ovarian cyst/tumor, options, and appropriate treatment by considering all factors, such as age, menstrual status, plan for fertility, medical conditions as well as possible nature or pathology of the cysts (based on results of various diagnostic modalities mentioned above).

Main treatments include:

1. Surveillance (close follow-up) If cysts are small, fluid-filled with no solid component (not as suspicious as a tumor), your gynecologist will recommend you watchfully notice your symptoms. Some medications may be prescribed to relieve your symptoms. Periodic follow-up visits for physical and pelvic exams as well as ultrasound to monitor the cyst for changes.
2. Medications Contraceptives may be prescribed for functional cysts, hormonal drugs for chocolate cysts, and antibiotics for tubo-ovarian abscess.
3. Surgery
   • Ovarian cysts which should be surgically removed for further diagnostic examination and/or treatment are:
     • Large mass, rapidly growing or causing symptoms in women of reproductive age, especially when the nature of the cyst is clinically ambiguous between functional cysts or tumors.
     • Persistent or growing mass after menopause.
     • Cysts due to non-tumor pathology but are large and/or refractory to medical treatment.
     • Clinical diagnosis of tumor, either benign or malignant, which needs to be surgically removed for definitive pathologic diagnosis.
   • Common surgical procedures
     • Ovarian cystectomy with preservation of ovarian tissue.
     • Unilateral oophorectomy (ovary removal), in case of a large cyst with no residual normal ovarian tissue.
     • Bilateral oophorectomy, in case of malignant ovarian cyst/ mass, along with removal of fallopian tubes, uterus, omentum, and retroperitoneal lymph nodes. Additional treatments may be prescribed accordingly. The doctor performing this surgery should be a skilled gynecologic oncologic surgeon.
   • Mode of surgical approach
     • Laparoscopic
     • surgery, a minimally invasive surgical procedure, utilizing surgical instruments inserted through several key-hole incisions through the abdominal or posterior vaginal wall.
     • Laparotomy, an open surgery approach through a large, single abdominal incision.

The gynecologist and the woman should have a thorough counseling session about the cyst/tumor, options of treatment, and her preference to reach a shared decision making for the most appropriate treatment approach.