Ovarian cysts are common and there are two general types, functional cysts and abnormal cysts. Functional cysts are quite normal. They develop as a result of the normal functions of an ovary. The most common types of functional cysts are follicular and corpus luteum cysts:
A follicular cyst forms when the follicle of an ovary gets bigger and fills with fluid as it produces an egg.
A corpus luteum cyst occurs after an egg has been released from the follicle. If pregnancy does not occur, the corpus luteum usually disintegrates. However, occasionally it swells with fluid or blood and remains on the surface of the ovary as a cyst.
Abnormal cysts result from abnormal cell growth. Sometimes abnormal cysts are caused by cancer, but 95% of cysts are not cancerous. The most common abnormal cysts are dermoid cysts. These cysts are similar to skin tissue on the outside and are filled with fatty material and sometimes bits of bone, hair, nerve tissue, and cartilage.
