Ovarian cysts
An ovarian cyst is a small sac inside the ovary filled with fluid. Most ovarian cysts are benign, and can burst by themselves, causing pain, but not being dangerous. Ovarian cysts may grow large and need to be removed. Cysts tend to develop in infancy and adolescence most often, but can occur during any life stage, and they tend to come and go without us knowing. Sometimes, what seems like a painful ovarian cyst may turn out to be another condition on investigation, like an ectopic pregnancy, ovarian torsion or appendicitis.
Symptoms of ovarian cysts
- Most cysts show no symptoms and are discovered incidentally
- Pain or discomfort in the lower abdomen
- Severe pain (from torsion or rupture) – sharp pain on one side of the pelvis
- Painful sex, especially deep penetration (dyspareunia)
- Problems defecating
- A desire to defecate
- Frequent urination due to pressure on the bladder
- Irregular menstrual cycle
- Abnormal vaginal bleeding
- Precocious puberty/early onset menarche
- A feeling of abdominal fullness or bloating
- Indigestion, heartburn, filling stomach quickly
- Endometriosis
- Polycystic ovarian syndrome (PCOS)
- Dull pain on one side
- Fast heart beat and low blood pressure
- Very tender abdomen
Why do ovarian cysts develop?
Most cysts occur during the normal process of follicular development during a normal menstrual cycle although some may occur due to a condition or disease. Remember, most cysts are benign and will resolve naturally.
Types of ovarian cysts
Functional cysts These are are the most common types of cysts and are a results of your normal menstrual cycle:
- Follicular cysts During each cycle your body normally grows cyst-like structures called follicles, which contain eggs, in preparation for ovulation. Normally one of these follicles grows big and bursts, releasing an egg (ovulation). When a follicle continues to grow with out releasing an egg it is called a follicular cyst and may cause pain. Excess follicle-stimulating hormone (FSH) can result in follicular cysts, or indeed a lack of a normal luteinising hormone surge at midcycle immediately prior to ovulation. Follicular cysts are usually larger than 2.5cm in diameter and there is a sense of discomfort and heaviness. Read more about follicular cysts.
- Corpus luteum cysts Corpus luteum cysts develop when dissolution of the corpus luteum fails to occur, resulting in the corpus luteum growing to 3cm in diameter. This type of cyst can cause dull pelvic pain on one side, and may rupture, causing blood loss. Read more about corpus luteum cysts.
Less common cysts
- Theca-lutein cysts Theca-lutein cysts occur with the luteinisation and hypertrophy of the theca interna cell layer after excess stimulation with human chorionic gonadotropin (hCG). They may occur during the luteal phase (post-ovulation phase of the menstrual cycle) or early pregnancy. These cysts have a tendency to torsion, haemorrhage and rupture, although they may also resolve spontaneously. Theca-lutein cysts can result in pain on both sides of the pelvis and ovarian enlargement.
- Luteoma of pregnancy This occurs when ovarian parenchyma tissue is switched out with luteinised stromal cells that can become hormonally active, producing androgens.
- Dermoid cyst – ovarian This type of cyst is a sac-like growth that appears on the ovary and contains hair and fatty tissue, though it is considered a tumour. It contains long hair, sebum, blood, fat, nails, teeth, thyroid tissue, eyes, cartilage, and bone. Read more about dermoid cysts.
- Neoplastic cyst A group of cells grows unexpectedly within the ovary, and could be malignant or benign.
- Teratomas A teratoma is a germ-cell tumour that contains embryonic germ layers – ectoderm, endoderm and mesoderm. Read more about teratomas.
Other cysts Although these health conditions are common they may or may not be symptomatic
- Endometriomas (chocolate cysts) Blood-filled cysts that appear out of the ectopic endometrium, and are associated with endometriosis. They may cause intense pain or no symptoms. Read more on endometriomas.
- PCOS Ovaries contain many cystic follicles due to hormonal imbalances that result in an oversensitivity to or an overproduction of androgens. The cysts of PCOS are generally smaller than other types of ovarian cysts and do not themselves cause pain, however, if you have PCOS you may be more prone to other types of ovarian cysts. Read more about PCOS
Risk factors for ovarian cysts include:
- Infertility treatments using ovulation induction – ovarian hyperstimulation syndrome
- Tamoxifen use
- Pregnancy (second trimester at hCG peak)
- Hypothyroidism
- Gonadotropins from the mother cause neonatal and fetal ovarian cysts
- Smoking tobacco
- High body mass index (BMI)
- Tubal ligation sterilisation
Cancerous ovarian cyst risks:
- Family history
- Getting older, elderly
- Caucasian
- Infertility
- Not bearing children
- History of breast cancer
- BRCA gene mutations
Diagnosis of ovarian cysts
An ultrasound is used to diagnose ovarian cysts, particularly if a mass is suspected. Each cyst will be examined. Some lab tests may be used, including a pregnancy test, urinalysis, and swabs to check for infection.
Treatment of ovarian cysts
Most ovarian cysts do not need treatment. In postmenopausal women, monitoring may be required. Some women will be put on oral hormonal contraceptives as a preventative, but cysts that already exist do not go away faster once on the pill. Any ovarian cysts larger than 5-10cm and any complex ovarian cysts may be surgically removed using a minimally invasive surgery with very small incisions (laparotomy and laparoscopy). In some cases, one or both ovaries may be removed (oophorectomy). A hysterectomy may also be performed, particularly in postmenopausal women, to help protect against cancer.
What else could it be?
- Water in the kidneys (hydronephrosis)
- Fluid-blocked fallopian tube/s (hydrosalpinx)
- Paraovarian cyst (near to ovary)
- Pedunculated leiomyoma (fibroid tumour)
- Pelvic kidney (normal kidney located in the pelvis)
- Pelvic lymphocele
- Peritoneal cyst
- Psoas abscess
- Tubo-ovarian abscess
- Tubal disease
- Abdominal abscess
- Ectopic pregnancy
- Twisted ovary (ovarian torsion)
- Polycystic ovarian syndrome (PCOS)
- Kidney stones (renal calculi)
- Inflamed fallopian tubes (salpingitis)
- Urethral diverticulum
- Possible impending miscarriage
- Appendicitis
- Diverticular disease
- Endometriosis
- Inflammatory bowel disease
- Large or small bowel obstruction
- Ovarian cancer
- Pelvic inflammatory disease
