In a premenopausal woman with a simple, unilocular ovarian cyst ≤5 cm, should I aspirate (pop) the cyst or manage it expectantly?

Do Not Aspirate Simple Ovarian Cysts ≤5 cm in Premenopausal Women

Aspiration (popping) of simple, unilocular ovarian cysts ≤5 cm in premenopausal women is contraindicated and offers no benefit—these cysts require no intervention and should be managed expectantly. 1, 2

Why Aspiration is Contraindicated

• Fine-needle aspiration for cytological examination of ovarian masses is explicitly contraindicated due to the risk of disseminating cancer cells if an unexpected malignancy is present 1, 2
• Transvaginal aspiration is specifically contraindicated for purely fluid cysts, particularly in postmenopausal women with cysts >5 cm 1, 2
• Even in premenopausal women, aspiration provides no diagnostic or therapeutic advantage—cytological evaluation of simple cysts is unreliable, with correct diagnosis in only 37.9% of cases 3
• Cysts that are aspirated frequently recur, making the procedure futile 3

The Evidence for Expectant Management

• Simple cysts ≤5 cm in premenopausal women are physiologic and require no additional management whatsoever 1, 2, 4
• The malignancy risk for unilocular cysts in premenopausal women is extraordinarily low at only 0.5-0.6% 1, 2
• In a cohort of 12,957 simple cysts in women under 50 years, zero malignancies were diagnosed 1
• These cysts are classified as O-RADS 2 (almost certainly benign, <1% malignancy risk) and require no follow-up 2, 4

Management Algorithm by Cyst Size

Cysts ≤5 cm (Your Patient)

• No follow-up imaging needed—reassure the patient this is a normal physiologic finding 1, 2, 4
• No tumor markers (CA-125) are indicated 2, 4
• Most functional cysts resolve spontaneously within 8-12 weeks without intervention 5, 6

Cysts >5 cm but <10 cm

• Follow-up ultrasound at 8-12 weeks (preferably during the proliferative phase) to confirm functional nature 1, 2
• If the cyst persists or enlarges, refer to gynecology or consider pelvic MRI 1
• Still, the vast majority remain benign and many will resolve 6

Cysts ≥10 cm

• Surgical management is indicated regardless of other features 1, 2

Critical Pitfalls to Avoid

• Do not operate prematurely on simple cysts <10 cm without an appropriate observation period—the malignancy risk is extraordinarily low and most resolve spontaneously 1, 2, 4
• Do not order CA-125 for simple cysts in premenopausal women—it is not indicated and performs poorly compared to ultrasound alone 2
• Do not assume persistent cysts are pathological—many benign neoplasms can be safely followed with malignancy risk <1% 1, 2
• The risk of acute complications (torsion, rupture) in benign-appearing lesions is only 0.2-0.4% 1

When to Escalate Care

• Development of solid components, septations, wall irregularity, or vascularity on follow-up imaging 1, 2
• Increase in size or morphological change during surveillance 2
• Persistent symptoms (pain, pressure, menstrual disturbance) despite conservative management 5, 6
• Any cyst that reaches ≥10 cm 1, 2