Endometrioma (chocolate) cysts

An endometrioma (chocolate) cyst is a very commonly found type of cyst in the ovary. Endometriomas are large, fluid-filled cysts that develop due to retrograde menstrual blood that contains endometrial cells. These cells proliferate in the ovary, over time developing into a cyst. Women with endometriosis have higher rates of endometriomas.

The build-up of menstrual blood starts to eventually leak out of the ovary, with the cystic mass made up of menstrual blood, endometrial tissue, and inflammatory molecules. Endometriomas are called ‘chocolate cysts’ because they are brown with old blood, making them look brown. If a endometrioma ruptures, it can cause the contents of the cyst to flow into the abdominal cavity, where it adheres.

     Symptoms of endometriomas

  • Asymptomatic
  • Excruciating pelvic pain, particularly at menstruation
  • Infertility
  • Menstrual irregularities

     Treating ovarian endometriomas
Treatment for ovarian endometriomas includes the surgical removal of the cyst. This is a delicate procedure with the goal to preserve as much ovarian function as possible. The surgeon will avoid using heat (to avoid ‘cooking’ the eggs), and separate the cyst carefully from the blood vessels. Removal of the ovaries is uncommon.

     Outcomes after surgery on endometriomas
Cystectomy performed on those with endometriosis diminished ovarian function due to the loss of ovarian follicles is common.