Benign endometrioid tumors often have cysts filled with dark blood, so although these are called endometriomas, they are sometimes referred to as chocolate cysts.

良性子宫内膜性肿瘤经常伴随着充满暗血的囊肿，所以尽管被称作子宫内膜异位瘤，它们也常被称为巧克力囊肿。

Because of this, endometriomas tend to bleed within the cyst cavity during menstruation, and over time, they fill up with old, dark blood and shed tissue - hence why they're sometimes also called " chocolate cysts" .

因此，在经期内，它的囊腔内可能会出血；久之囊内就充满了陈旧、暗黑色的血和脱落组织，这也是它们又被称为巧克力囊肿的原因。