Ovarian cysts are fluid‐filled pockets or sacs that grow within or on the surface of an ovary. There are multiple types of ovarian cysts, the majority of which are harmless, causing no symptoms and disappearing on their own without treatment within a few months. They can range in size from a few centimeters to over a foot in length. Many women will develop ovarian cysts at some point during their lives. They are one of the most common reasons women seek gynecologic consultation.

Types of Ovarian Cysts

Functional Cysts

The majority of ovarian cysts form naturally as a result of menstrual cycles during a woman’s reproductive years. Leading up to ovulation, your ovaries grow small follicles. The follicles release hormones and expel the egg when you ovulate. Sometimes, a normal follicle will continue to grow and retain fluid after your menstrual cycle; this is known as a functional cyst. They are almost always harmless, typically shrinking and disappearing on their own within four to eight weeks.

Benign Neoplastic Cysts

These types of cysts are rare and present in a variety of forms. These cysts are characterized by abnormal tissue growth. The most common type of benign neoplastic cysts is the cystic teratoma, also known as a dermoid cyst. Developing from a germ cell, these cysts can contain multiple types of tissue, including sebaceous glands, skin cells or hair follicles. Sometimes these cysts cause no symptoms, but occasionally they can produce other medical complications and pelvic pain. Usually these types of cysts do not resolve on their own.

Endometriotic Cysts

Developing as a result of endometriosis, these cysts develop when endometrial-like tissue grows outside of the uterus and becomes attached to the ovaries. During a menstrual cycle, hormones trigger uterine tissue to be shed after ovulation and exit the body. Endometrial tissue on the ovaries cannot be shed, causing the tissue to accumulate, and form dark, reddish brown cysts. For this reason, endometriotic cysts are commonly referred to as “chocolate cysts.” These cysts usually do not resolve spontaneously, and if they rupture, can cause pelvic pain, adhesions and infertility.

Malignant Cysts

The vast majority of cysts are benign, but any type of cyst can become malignant or cancerous. A malignant cyst, or tumor, indicates ovarian cancer. A cyst is suspected to be malignant when certain characteristics are observed during a physical exam, ultrasound or in a patient’s medical history. In this situation, a biopsy or complete removal of the cyst is recommended.

Complications

Rupture

It is relatively common for a woman of reproductive age to have an ovarian cyst rupture. This can be painless and go unnoticed, but is also be associated with the sudden onset of lower abdomen pain, typically on one side of the body. The pain usually begins during physical activity, which caused the cyst to rupture.

Other conditions with similar symptoms include ovulation pain, ectopic pregnancy and ovarian torsion, which must be ruled out before a treatment plan can be determined. Often ruptured cysts do not need treatment beyond pain medication and observation, but if a woman’s blood pressure becomes unstable or bleeding continues, surgical intervention may be necessary.

Ovarian Torsion

Sometimes ovarian cysts become enlarged to such a degree that they can cause the ovary to twist out of its natural position, partially or fully inhibiting blood supply to the ovary. This is called ovarian torsion. Symptoms are acute and sudden, and include lower abdominal pain, often unilateral, as well as nausea or vomiting. It is among the most common gynecologic emergencies, requiring surgical intervention to correct.