Sometimes medical syndromes are named long before they are fully understood. Take polycystic ovarian syndrome, or PCOS, which affects as many as 10 percent of women of childbearing age, often impairing their fertility. But not all of these women have polycystic ovaries, a fact that can result in misdiagnosis. As it turns out, cysts — sacs of fluid on the ovaries — are just one manifestation of a complex hormonal condition.Sometimes medical syndromes are named long before they are fully understood.Take polycystic ovarian syndrome, or PCOS, which affects as many as 10 percent of women of childbearing age, often impairing their fertility.But not all of these women have polycystic ovaries, a fact that can result in misdiagnosis. As it turns out, cysts — sacs of fluid on the ovaries — are just one manifestation of a complex hormonal condition.