Dr Lee Keen Whye explains the difference between the two and the
various ways of identifying and treating them.
What are uterine fibroids and ovarian cysts?
Gynaecology is the study of female diseases as opposed to obstetrics which is the study of pregnancy and its related disorders. The three most common gynaecological problems which may need surgery are uterine fibroids, ovarian cysts and heavy menstrual bleeding. The commonest confusion when a female is diagnosed with a pelvic growth or tumour is to differentiate a fibroid (myoma) from ovarian cyst and vice versa.
Fibroid and ovarian cysts are the two most common female pelvic growths or tumours which cause confusion and identification amongst patients. Even the term ‘tumour’, which just means a growth and does not indicate whether it is benign (non-cancerous) or a cancer, can be confusing.
Fibroid or myoma (Latin) is commonly called ‘meat’ or ‘muscle’ tumour colloquially. This is because the growth or tumour arises from the smooth muscles of the uterus.
The Indonesians called it ‘myom’. Fibroids are common non-cancerous growths found in about 10% to 20% of women in the reproductive age group. The exact cause is unknown but is believed to be due to a localised hormonal imbalance of the uterus. Female hormones and drugs or herbs containing traces of oestrogen can stimulate the growth of fibroids. Fortunately, the risk of fibroids turning cancerous is less than 0.5%. See picture 1.
How do fibroids present?
Most fibroids are asymptomatic and are often discovered during routine health screening. Often ladies regard a bulge at the belly as ‘fat’ collection associated with overeating, lack of exercise or simply middle age paunch. The bulge can turn out to be a silently growing fibroid.
Often ladies regard a bulge at the belly as ‘fat’ collection associated with overeating, lack of exercise or simply middle age paunch. The bulge can turn out to be a silently growing fibroid.
When fibroids multiply in numbers or enlarge, they can cause pressure symptoms on surrounding organs like the bladder, rectum, backbone and pelvis. Patient may complain of urinary symptoms, rectal symptoms, backache and bloatedness. In severe cases, it may cause obstruction to the urinary flow leading to kidney damage. Fibroids are known to cause heavy menstrual bleeding and in some instances, infertility, miscarriage and pre-term labour.
Treatment of fibroids
Small fibroids can be observed and in menopause, they do shrink in size. However, big fibroids that do not shrink after menopause need to be monitored carefully
for fear of them turning cancerous. The symptomatic fibroid needs medical attention. Drugs associated with male hormone and menopause hormone may provide temporary relief but can cause side effects like masculinising changes ( male voice, hair growth, acne, etc.) or menopause changes (dry skin, hot flushes, osteoporosis, etc.). There are newer techniques like uterine artery embolisation or ultrasound ablation, but these are for selective cases in specialised centers.
Picture 2. Uterine Fibroids (F) Picture 3. Myomectomy Picture 4. Uterus repaired after Picture 6. Bilateral ‘chocolate’ cysts
How do fibroids present?
Most symptomatic fibroids are removed surgically via laparoscopic minimally invasive surgery (keyhole)(See Pictures 2, 3, 4) or laparotomy (open surgery). The choice of laparoscopic or laparotomy depends on the surgeon’s skill, equipment level, size, number and location of the fibroids. Whether it would be a myomectomy (removal of fibroid) or hysterectomy (removal of womb) will depend on the age, fertility status, and other associated medical factors. The best option is often arrived after consultation with the gynaecologist. Figure 1 shows a guide for myomectomy or hysterectomy.
When to perform
• Desire for child bearing
• Emotional attachment to womb
• Completed family
• Prevent recurrent fibroids
• Multiple fibroids
• Older women
• Associated uterine problems e.g. CIN, menorrhagia
Ovarian cysts are fluid filled tumours that arise from one or both ovaries. The cyst wall or capsule is soft and may appear round, oval or irregular in shape. The cyst content is liquid, mostly fluid, filled with water (clear cyst), filled with blood (haemorrhagic or chocolate cyst) or mixed with other human tissues like hair, fat, tooth, cartilage, bone etc. See picture 5. There are many types of ovarian cysts but I will simplify them into four main types for easy understanding.
1) Functional cyst
This is by far the commonest cyst reported daily in ultrasound reports causing the most unwarranted anxiety to the patient. These functional ‘cysts ‘are mostly physiological in nature and best known as ovarian follicles (preovulation) and corpus luteum (post ovulation). These are natural occurrences in normal menstruating females. Benign cysts can also be found in females on fertility drug treatments,
having hormonal imbalances or on progestogenic intra uterine devices like Mirena. Almost all functional cysts disappear with time and rarely require surgery.
2) Endometriotic cyst
Endometriotic cyst is commonly known as ‘chocolate cyst’ and colloquially called ‘blood’ cyst. The ‘chocolate’ or ‘blood’ is actually menstrual blood produced by the endometrium (menstrual lining) of the uterus that has escaped into the pelvis eroding or invading into pelvic organs giving rise to a condition called endometriosis. The invading menstrual lining engulfs itself to form a capsule and hence an endometriotic cyst is formed with a collection of menstrual blood and secretion within. When an endometriotic cyst ruptures, spillage of ‘chocolate’ or altered ‘blood’ is poured onto surfaces of the pelvis, rectum, uterus, ovary, intestine and bladder giving rise to discomfort and pain. The resulting aftermath is inflammation, scarring and destruction of normal pelvic anatomy. Hence dysmenorrhoea, pelvic pain and infertility are often encountered. Fortunately, endometriotic cysts are mostly benign but their appearance can be threatening and suspicious looking. See picture 6.
3) Benign (non-cancerous) ovarian cyst
The three most common types are serous cystadenoma (30% cancer risk), mucinous cystadenoma (5 to 10% cancer risk) and dermoid cyst (teratoma) which can contain human structures like hair, tooth, fat, cartilage, bone etc. The cause of these cysts is unknown.
4) Ovarian Cancer
Ovarian cancer can be considered the deadliest of all female cancers because it is often discovered late.
The cyst content is liquid, mostly fluid, filled with water, blood or mixed with other human tissues…
It occurs in roughly 5% of all ovarian cysts. In its early stage, it is asymptomatic and hard to detect. In its later stage, it causes abdominal bloatedness, pain, loss of appetite and weight and spread to other parts of the body.
What are the common symptoms of ovarian cyst?
An ovarian cyst is generally asymptomatic when it is small. When it enlarges it can cause abdominal swelling, discomfort and pain. Severe pain can result when the
cyst ruptures or twists (torsion). It may also put pressure on bladder causing urinary symptoms or on the rectum causing bowel symptoms.
Do I need an operation?
The need to operate depends on the severity, size of cysts, number of cysts, and complexity of cysts and prevention of complications like rupture, torsion, enlargement and suspicion of cancer. The commonly done operations for ovarian cysts are cystectomy, oophorectomy and total hysterectomy with bilateral oophorectomy. See Figure 2 for explanation.
Op erations for ovarian cyst
i. Ovarian cystectomy – removal of cyst wall
and contents with conservation of the remaining
ovary for hormonal function. Younger women
would prefer this. See pictures 7, 8, 9.
ii. Oophorectomy – removal of whole ovary and
cyst. This is done if most or the entire ovary is
destroyed by the cyst.
iii. Total hysterectomy with bilateral
oophorectomy – removal of both ovaries
and uterus for fear of cancer developing or for
The approach to the operation whether via laparascopy or laparotomy and the surgical procedures are best discussed with the attending gynaecologist.
It is advised that all sexually active females should see a doctor as early as possible for pap smear, cervical cancer
vaccination advice, breast examination, pelvic examination (with or without ultrasound) and contraceptive or fertility advice. Routine examinations like an annual check up and pre-employment screening have picked up a fair number of asymptomatic growths.
Any female regardless of age or sexual activity should consult a doctor if she has gynaecological related complaints like heavy menses, abnormal vaginal bleeding, painful menses, pelvic discomfort, bloatedness or palpable pelvic lump.
A combined vaginal and abdominal examination is often able to detect a pelvic tumour, and a fibroid feels harder than a cyst to the doctor. With the help of an ultrasound scan, the differentiation of a cyst from a fibroid is made easier. Occasionally, an MRI scan is requested to gauge the likelihood of encountering cancer for the pre-operative counselling of the patient. But the definitive diagnosis still rests with the histology of the resected tumour.
A benign fibroid or cyst can lead to pain, distortion of pelvic anatomy, menstrual problems, side effects on pelvic organs and infertility.
A cancerous growth can bring about morbidity, poor quality of life and death. Hence, early detection of pelvic tumours, be it ovarian cyst or fibroid, can prevent further harm to the health of the individual and keep healthcare costs low.
Dr Lee Keen Whye
MBBS (Singapore), FRCOG (UK), FAMS (Singapore)
Consultant Obstetrician & Gynaecologist
Dr Lee is a Consultant Obstetrician & Gynaecologist at the Gleneagles Medical
Centre with special interest in hysteroscopy and laparoscopy. He has done
many international lectures and preceptored many endoscopic workshops in
Indonesia, Taiwan, Korea, India and Myanmar. He is also a founder member
of the Asia-Pacific Association of Gynaecological Endoscopists (APAGE).
In 2003, Dr Lee was awarded the prestigious Benjamin Henry Sheares
Gold Medal by the Obstetrical and Gynaecological Society of Singapore.