Benign Ovarian Cysts

A benign ovarian cyst is a fluid-containing ovarian lesion without clinical, ultrasound, or laboratory evidence strongly suggesting malignancy. The most common benign cysts are functional cysts, which arise from the normal menstrual cycle rather than from a separate disease process. A follicular cyst develops when a dominant follicle fails to rupture or regress. A corpus luteum cyst develops when the post-ovulation corpus luteum persists, enlarges, or hemorrhages. The word benign should not make an acute presentation seem harmless. A cyst can be benign in its cellular behavior and still cause torsion, rupture, hemoperitoneum, pain, or pressure symptoms. Conversely, a large or complex mass is not automatically malignant. Experienced assessment combines the patient’s age and menopausal status, symptoms, hemodynamic stability, ultrasound morphology, and change over time. Most functional cysts disappear spontaneously within two to three menstrual cycles. That expected behavior explains why observation is usually safer than immediate medication or surgery when the patient is stable and the imaging appearance is reassuring. Persistence, growth, suspicious morphology, or a change in symptoms moves the patient out of a simple functional-cyst pathway and...