What is a chocolate cyst?

A chocolate cyst is the popular name for an endometriosis cyst on the ovary (endometrioma). It is named after the dark, brown, thick fluid inside. Not everyone with endometriosis has a chocolate cyst, and not every ovarian cyst is one; a doctor tells them apart using imaging.

How are chocolate cysts and endometriosis related?

The ESHRE guideline describes endometriosis in three forms: superficial peritoneal disease, ovarian endometrioma and deep endometriosis. An endometrioma is only one of these. Having a cyst does not show whether the disease is also elsewhere; that needs a doctor’s examination and imaging.

How is it imaged?

Ovarian endometriomas can be found with ultrasound or MRI. ESHRE notes that endometrioma and deep disease can be identified by imaging, whereas superficial disease can be missed. That is why a normal ultrasound does not rule out endometriosis. Details are on our diagnosis page.

What is discussed for treatment?

The decision is individual; your age, symptoms, the characteristics of the cyst and your wish to conceive all matter. Some general points from the guideline:

• When surgery is done, ESHRE says that removing the cyst wall (cystectomy) reduces recurrence of the cyst and of pain compared with draining and burning it.
• Specific caution is advised to minimise damage to the ovary during surgery.
• Routine surgery for endometrioma before IVF is not recommended, because there is no evidence it raises live birth rates and it may harm ovarian reserve. Surgery may be considered for reasons such as pain or access to follicles.

These are general guideline points; the right path for you is decided with your doctor. For the broader picture, see the treatment page.