What is the term for a fluid-filled sac that forms inside an ovary?

The term for a fluid-filled sac that forms inside an ovary is an ovarian cyst. These cysts are typically benign and can occur during the menstrual cycle as a normal part of ovarian function. They often develop when the follicles, which contain eggs, do not release the egg as they should, leading to fluid accumulation. While many ovarian cysts are harmless and may resolve on their own, they can sometimes cause discomfort or complications if they grow larger or rupture.

Fibroma refers to a benign tumor made up of fibrous or connective tissue, rather than a fluid-filled structure within the ovary. Seroma is a collection of clear serous fluid that can occur in any tissue after surgery or injury, but it is not specific to the ovarian tissue. Adenoma is a type of tumor that arises from glandular tissue, which again does not relate to the formation of a fluid-filled sac in the ovaries. Thus, the correct identification of an ovarian cyst is crucial in understanding these distinctions in female reproductive health.