Chocolate Cyst - What it is and What to Do About It

A woman's uterus is lined on the inside with a mucus membrane called endometrial tissue. At times, a small part of this tissue is shed into the pelvic cavity or on the surface of the organs in the pelvis such as the ovaries and the fallopian tubes. This is a medical condition known as endometriosis. This tissue responds to the hormones in a woman's monthly cycle whether the tissue is in the uterus or not. Usually when the hormone is released, it sends a signal to the uterus to prepare for possible pregnancy. The tissue thickens in response and if pregnancy does not occur, the tissue is shed as menstrual blood. The tissue in the uterus flows out through the vagina but that within the pelvic cavity has nowhere to go and therefore accumulates. A chocolate cyst is the cyst that forms from the endometrial tissue that invades the ovaries. It is filled with old blood, brown in color, hence the name "chocolate cysts". It could also be called endometrial cyst or endometrioma.

The size of a chocolate cyst varies and though they can sometimes be painful, especially during menstruation, they are not usually bothersome. Chocolate cysts can rupture, spilling its contents into the pelvic area. When this occurs it is painful and the contents of the cyst can cause the organs it spills on, to adhere together. When this happens with the fallopian tubes or ovaries, it can result in infertility.

Chocolate cysts can be diagnosed through laparoscopy, a surgical procedure in which two small incisions are made around the navel and a laparoscope inserted to get a viewing of the contents of the organs within. Diagnosis can also be made using trans-vaginal ultrasound or a blood test called ca 125 test. Women who have endometriosis have high levels of the protein named cancer antigen 125 (ca 125) in their blood.

Once detected, chocolate cysts can be treated through surgery or with medication. The size of the cyst will determine the extent and type of surgery; if the chocolate cyst is small a surgery called cystectomy will be performed to remove the cyst only, but if the cyst is large and depending on what the diagnosis is, a more radical surgery known as an oophorectomy, that is, removal of the ovary or ovaries, will be done.

Treatment through medication is usually through hormonal therapy using oral contraceptive pills to stop ovulation. Progestational agents are also used for treatment of chocolate cyst. Gonadotropin releasing hormone agonists (GnRH) have been used for over twenty years as a means to help control the menstrual cycle, but the effect of treatment using medication is only short term and usually requires other additional medications to be taken to reduce side effects such as weight gain and hot flashes that are common with hormonal therapy.