A cyst that enlarges due to hormonal stimulation and is typically defined as greater than 3 cm is classified as what?

• A. Functional cyst
• B. Dermoid cyst
• C. Endometrioma
• D. Serous cystadenoma

Answer: (A)

Functional ovarian cysts come from normal ovarian activity and are driven by hormonal cycles. When a follicle enlarges or the corpus luteum persists after ovulation, it forms a cyst that can grow in response to the hormones at play. Because their growth is tied to hormonal stimulation, these cysts are often described as larger than a typical physiologic follicle, with a common size threshold around 3 cm used to categorize them. They are usually benign and tend to resolve on their own within a few menstrual cycles.

Dermoid cysts (mature cystic teratomas) are not related to hormonal cycles and arise from germ cells, often having mixed tissue and more complex imaging features. Endometriomas are associated with endometriosis and have a characteristic “chocolate” internal content on imaging. Serous cystadenomas are epithelial tumors that can become large but are not driven by normal ovarian hormonal activity.