Chocolate cyst: An endometrioma (commonly known as a

An endometrioma (commonly known as a chocolate cyst) is a type of cyst that forms when endometriosis affects the ovaries. They develop deep within the ovaries and are filled with old blood and endometrial-like tissue, giving them their characteristic dark, chocolate-like appearance. Chocolate ovarian cyst: Ovarian endometrioma means cysts on ovaries filled with tissue similar to the uterine lining. Learn more about the symptoms, causes and treatment of ovarian endometrioma here. Chocolate cysts are noncancerous, fluid-filled cysts that typically form deep within the ovaries. They get their name from their brown, tar-like appearance, looking something like melted... Chocolate cysts primarily affect women of reproductive age, typically between their late teens and early 40s. While any woman can develop these cysts, they are more commonly found in those with endometriosis, a condition where tissue similar to the lining of the uterus grows outside the uterus.