17β-Hydroxysteroid dehydrogenase type I and aromatase in ovarian cortical inclusion cysts.

Summary: Scientists are investigating how ovarian cancer begins, looking closely at microscopic cysts found within the ovary's outer layer. By analyzing tissue samples from women aged 23 to 80, researchers discovered that these tiny cysts are not inactive; instead, they contain the specific enzymes needed to produce estrogen, as well as the receptors to use it. This machinery was found more often in the cysts than on the ovary surface itself, particularly in cysts resembling fallopian tube tissue. This suggests that these cysts can manufacture their own fuel—estrogen—which may play a critical role in the early development of ovarian cancer.