One of the most common questions women ask after an ultrasound is: “I have an ovarian cyst — does that mean I have cancer?” The short answer is: almost certainly not. But the longer answer requires understanding what ovarian cysts are, how they differ from ovarian cancer, and when to be concerned.
What Is an Ovarian Cyst?
An ovarian cyst is a fluid-filled sac that forms on or inside an ovary. They are extremely common — most women will develop at least one ovarian cyst during their lifetime, usually without ever knowing it. The vast majority of ovarian cysts are benign (non-cancerous) and resolve on their own within a few months.
Types of Ovarian Cysts
Functional Cysts (Most Common)
These form as part of the normal menstrual cycle and are almost always harmless:
- Follicular cysts: Form when a follicle does not release an egg and continues to grow
- Corpus luteum cysts: Form after the egg is released, when the follicle fills with fluid
Other Benign Cysts
- Dermoid cysts: Contain tissue like hair, skin, or teeth — unusual but almost always benign
- Endometriomas: Related to endometriosis; can cause pain
- Cystadenomas: Fluid-filled cysts that can grow large but are usually not cancerous
What Is Ovarian Cancer?
Ovarian cancer occurs when cells in the ovary grow abnormally and form a malignant tumour. Unlike simple cysts, ovarian cancer tumours have complex characteristics visible on imaging, and they do not resolve on their own. They grow, spread, and can be life-threatening if not treated.
Key Differences Between Ovarian Cysts and Ovarian Cancer
| Feature | Benign Ovarian Cyst | Ovarian Cancer |
|---|---|---|
| Appearance on ultrasound | Simple, smooth walls, fluid-filled | Complex, solid areas, irregular walls |
| Resolves on its own | Often yes (within 1 to 3 months) | No — grows over time |
| Age group | Any age, common in reproductive years | More common after menopause |
| CA-125 levels | Usually normal | Often elevated (but not always) |
| Symptoms | Often none; may cause pelvic pain | Bloating, fullness, pelvic pain, urinary changes |
When Should You Be Concerned About an Ovarian Cyst?
Most cysts found incidentally on ultrasound do not need immediate treatment. However, see a specialist if:
- The cyst is large (over 5 cm)
- The cyst has solid components, thick walls, or irregular features
- You are postmenopausal (any new ovarian cyst after menopause needs evaluation)
- Your CA-125 level is elevated
- The cyst does not resolve after 2 to 3 months of observation
- You have symptoms like persistent bloating, pelvic pain, or feeling full quickly
How Are They Diagnosed?
A combination of transvaginal ultrasound, CA-125 blood test, and sometimes MRI or CT scan are used to evaluate an ovarian mass. In some cases, laparoscopic surgery is needed to examine and remove the cyst for definitive diagnosis.
Do Not Self-Diagnose
While the odds are strongly in favour of a benign cyst, only a specialist can accurately assess the risk. The features of a cyst on imaging, your age, your symptoms, and your blood test results all need to be evaluated together.
If you have been told you have an ovarian cyst — especially if you are postmenopausal, or if the cyst has complex features — please consult a gynecologic oncologist for a thorough evaluation.
Dr. Monisha Gupta is a Gynecologic Oncologist at Fortis Hospital, Shalimar Bagh, New Delhi, specialising in the diagnosis and treatment of ovarian and other gynecologic cancers.
