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, an underlying condition may be revealed, 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
- Polycystic ovarian syndrome (PCOS)
- Dull pain on one side
- Fast heart beat and low blood pressure
- Very tender abdomen
Why do ovarian cysts develop?
There are a few reasons why cysts may develop of the ovaries besides the normal process of follicular development during a normal menstrual cycle. Remember, most cysts are benign and will resolve naturally.
- PCOS, and subsequent ovarian hyperstimulation syndrome
- Hyperreactio luteinalis – abnormal, hypersensitivity of the ovaries to blood hCG
Risk factors for ovarian cysts include:
- Infertility treatments using ovulation induction – ovarian hyperstimulation syndrome
- Tamoxifen use
- Pregnancy (second trimester at hCG peak)
- 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
- 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.
Types of cysts
- Follicular cysts
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.
- 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). These cysts have a tendency to torsion, haemorrhage and rupture. These cysts may be due to excess maternal androgens, but can resolve spontaneously as hCG levels return to normal. Theca-lutein cysts may result in pain on both sides of the pelvis and ovarian enlargement.
- Luteoma of pregnancy
This occurs when the ovarian parenchyma 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.
A teratoma is a germ-cell tumour that contains embryonic germ layers – ectoderm, endoderm and mesoderm. Read more about teratomas.
- Endometriomas (chocolate cysts)
Blood-filled cysts that appear out of the ectopic endometrium, and are associated with endometriosis. Read more on endometriomas.
Ovaries contain cystic follicles due to hormonal imbalances that result in an oversensitivity to or an overproduction of androgens. Read more about PCOS
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
- Kidney stones (renal calculi)
- Inflamed fallopian tubes (salpingitis)
- Possible impending miscarriage
- Diverticular disease
- Inflammatory bowel disease
- Large or small bowel obstruction
- Ovarian cancer
- Pelvic inflammatory disease