Ovarian cyst
An ovarian cyst is a fluid-filled sac that forms inside an ovary or on its surface. It is one of the commonest findings in gynaecology: in women of…
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An ovarian cyst is a fluid-filled sac that forms inside an ovary or on its surface. It is one of the commonest findings in gynaecology: in women of childbearing age these sacs appear and disappear all the time, usually without giving any sign of themselves. Most settle within one to three menstrual cycles and need nothing done about them. The ones that deserve attention are different: those that grow, those that fail to disappear over time, those that hurt, and those found for the first time after the menopause.
Where a fluid-filled sac in the ovary comes from
The ovaries are a pair of organs about the size of a large grape, sitting on either side of the womb. Each month an egg ripens in one of them and a follicle forms around it: a small fluid-filled sac that protects the cell while it grows. Halfway through the cycle the follicle opens, the egg is released, and a temporary gland called the corpus luteum takes its place and prepares the body for a possible pregnancy.
A hitch at any of these steps leaves a cavity behind. The follicle may fail to open and go on filling with fluid. The corpus luteum may fail to shrink away on time, or may fill with blood. That is how functional cysts arise: they are a direct by-product of the ovary doing its ordinary job, not a sign of disease. It is also why they are almost never seen in girls before their first period or in women past the menopause — where there is no ovulation, there is no raw material for such a sac.
The types you may hear about
Functional cysts are the commonest. They rarely exceed a few centimetres, do not turn cancerous and usually vanish on their own. Hormonal contraception that suppresses ovulation makes new ones less likely, but it will not dissolve a cyst that has already formed.
The remaining kinds grow independently of the cycle, and each has its own origin:
- endometrioma — a collection of old blood in a patch of endometriosis, with thick, dark contents;
- dermoid cyst — present from birth, developing from germ cells, and capable of containing fat, hair or rudimentary teeth; usually found in younger women;
- cystadenoma — an overgrowth of the cells covering the ovary, which can reach a considerable size;
- a malignant tumour — rare, but it is the reason gynaecologists take such care over lumps that refuse to disappear, and over anything found after the menopause.
Polycystic ovary syndrome stands apart. Despite the name it is not a collection of cysts but a hormonal disorder in which the ovary holds on to many small, unripened follicles. It is managed differently: through the cycle and the metabolism rather than through surgery.
What a woman actually notices
Most often, nothing at all. The cyst turns up on a routine scan or during tests done for a completely unrelated reason, and that is the ordinary course of events rather than a missed illness.
When the sac grows large, presses on neighbouring organs or goes with endometriosis, symptoms appear:
- a dull or dragging pain low in the tummy, often only on one side;
- a feeling of fullness or bloating, with waistbands becoming tight;
- feeling full after only a few mouthfuls of food;
- pain during sex;
- needing to pass urine more often, or difficulty opening the bowels — a large cyst simply presses on the bladder and rectum;
- changes in the cycle: periods arriving off schedule, heavier or lighter than usual.
None of these points to a cyst on its own. Fibroids, infection of the tubes and ovaries, and bowel conditions all behave the same way. The question is settled by examination and a scan, not by the list of complaints.
Pain that must not wait until morning
Two complications turn a harmless finding into an emergency. Torsion: the ovary and cyst twist around the ligament that holds them and pinch off their own blood supply, and without circulation the tissue dies within hours. Rupture: the wall gives way and the contents, along with blood, spill into the abdominal cavity.
Call an ambulance — in Spain, Italy, Portugal, Poland and Ukraine the single European number is 112 — if:
- pain low in the tummy comes on suddenly, is sharp, is getting worse and stops you straightening up;
- the pain is joined by nausea and vomiting;
- you become pale, break out in a cold sweat, feel very weak, dizzy or faint;
- the pain comes with a high temperature.
An ectopic pregnancy, appendicitis and severe infection of the tubes and ovaries all begin in exactly the same way, and they cannot be told apart without tests — one more reason not to sit an attack out at home. For a woman of childbearing age the first thing done in the emergency department is a pregnancy test: an ectopic pregnancy is more dangerous than any cyst and calls for an entirely different decision.
How a cyst is identified
The mainstay is ultrasound. A probe passed into the vagina gives a far sharper picture than scanning through the abdominal wall: the doctor can see the size of the sac, the thickness of its wall, and whether it contains partitions, solid areas or a blood supply of its own. Those features separate a simple functional cyst from a lump that has to be watched or removed.
If the picture is reassuring, the scan is repeated a few weeks or months later. A sac that has gone by then was functional, and there is nothing further to investigate.
A CA-125 blood test is requested selectively and is never read apart from the scan. The marker rises with endometriosis, fibroids and pelvic infection, and in younger women simply during a period. A high figure on its own does not mean cancer, and a normal one does not rule it out. What carries weight is the combination: age past the menopause, a growing lump with a complex structure, and a raised marker. That pattern earns a referral to a gynaecological cancer specialist.
Watching or operating
The decision rests on three things: how the cyst looks on the scan, whether it is causing trouble, and whether the menopause has been passed.
A simple thin-walled sac of a few centimetres in a woman still having periods calls for observation rather than surgery. The follow-up scan usually shows it has gone. After the menopause the same finding is treated more strictly: with no ovulation it cannot be functional, so follow-up runs longer and in more detail.
Surgery is offered when a cyst is large, is not shrinking with time, causes persistent pain, or looks suspicious in structure. Usually this means laparoscopy: a camera and instruments go in through a few small cuts in the abdominal wall and the cyst is shelled out, with the ovary itself preserved wherever possible. Open surgery through a single incision is chosen for very large lumps and where cancer is suspected, when it matters to lift the cyst out whole without breaking its capsule. Whatever the approach, the tissue removed goes for examination under the microscope — only that gives the final answer about its nature.
Draining a cyst with a needle is not used as a treatment in its own right: the sac fills up again, and spilled contents make an accurate diagnosis harder.
The first weeks after surgery
Tummy pain, and after laparoscopy shoulder pain as well from the gas irritating the diaphragm, lasts a few days and then settles. The cuts heal within a week or two, but sport and heavy lifting are off the table for about six weeks, and longer after open surgery.
See a doctor the same day if, after going home, you develop:
- a temperature above 38 °C, or shivering;
- increasing pain and swelling of the tummy instead of steady improvement;
- heavy vaginal bleeding;
- discharge with an unpleasant smell;
- redness, swelling or discharge from the wounds;
- pain, swelling or redness in the calf, or breathlessness — this is how a clot shows itself, and the risk is raised after any operation.
The laboratory result is usually ready in two or three weeks. It is worth taking it to a follow-up appointment even if you feel entirely well.
Cysts and the chance of pregnancy
A cyst by itself rarely stands in the way of conceiving, and a functional one has no effect on fertility at all. The difficulty comes from what causes certain cysts: endometriosis alters the tubes and the quality of ovarian tissue, and polycystic ovary syndrome disturbs ovulation.
During surgery the aim is to keep as much healthy tissue as possible, so as a rule only the cyst itself is taken. Even if one whole ovary has to go, the other carries on producing hormones and eggs, and pregnancy remains possible. Removing both ovaries before the menopause brings it on early and ends the chance of conceiving with your own eggs; that step is taken only for compelling reasons and is always discussed in advance.
If you are planning a family, say so before the operation rather than afterwards. The extent of surgery is agreed beforehand, and with endometriomas it is worth a separate conversation about ovarian reserve.
Online consultation
A cyst found on a scan frightens people more than it deserves, and a report full of measurements and partitions rarely makes sense without help. In an online consultation a gynaecologist goes through your scan report, tells you whether the finding looks functional, whether a repeat scan is needed and exactly when, and whether a CA-125 test makes sense in your situation.
Preparing is straightforward: gather every scan report you have, note the dates of your recent periods and the length of your cycle, and list the medicines you take, contraception included. If you keep a record of the pain, bring it along — the character of the pain and how it tracks the cycle tell a doctor more than you might expect. Results can be interpreted, follow-up planned and the need for a face-to-face visit decided remotely. Sudden severe abdominal pain, however, is not a job for an online appointment: that needs examination and a scan within the hour.
This material is for information only and does not replace medical advice.
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