What is the best treatment plan for a 20-year-old female patient with a simple ovarian cyst?

Management of Simple Ovarian Cyst in a 20-Year-Old

For a 20-year-old with a simple ovarian cyst ≤5 cm, no additional management or follow-up is required; for cysts >5 cm but <10 cm, perform a single follow-up ultrasound in 8-12 weeks during the proliferative phase to confirm resolution or reassess for wall abnormalities. 1

Risk of Malignancy

• Simple ovarian cysts in premenopausal women under 50 years have essentially zero risk of malignancy, with no cancers identified among 12,957 simple cysts in this age group over 3 years of follow-up 1
• The overall risk of malignancy in simple cysts among premenopausal women is approximately 0.5% (3 of 657), though this data is from surgically selected cases and likely overestimates true risk 1
• Simple cysts are classified as O-RADS 2 (almost certainly benign) with <1% malignancy risk regardless of size 1, 2

Size-Based Management Algorithm

Cysts ≤3 cm

• These are considered physiologic (normal follicles) and require no follow-up 1

Cysts >3 cm to ≤5 cm

• No additional management is required 1
• These cysts do not need follow-up imaging 1, 2

Cysts >5 cm to <10 cm

• Perform follow-up transvaginal ultrasound in 8-12 weeks 1, 2
• Schedule the follow-up during the proliferative phase (after menstruation) to allow functional cysts time to involute 1, 2
• The rationale for follow-up is that larger cysts are more challenging to evaluate completely on initial imaging, and this confirms whether the cyst is functional or identifies any wall abnormalities that may have been missed 1

Cysts ≥10 cm

• Refer to gynecologist for management 1
• These exceed the threshold for routine observation due to incomplete evaluation risk 1

Follow-Up Imaging Specifications

• Use transvaginal ultrasound as the primary modality, supplemented with transabdominal approach if needed for complete visualization 1
• Include color or power Doppler to evaluate for any developing solid or vascular components 1
• If the cyst persists, enlarges, or develops concerning features at 8-12 week follow-up, refer to gynecology 1, 2

Critical Pitfalls to Avoid

• Do not perform unnecessary surgery on simple cysts, as the vast majority are functional and will resolve spontaneously, even in larger sizes up to 10 cm 1
• Do not schedule routine surveillance for cysts ≤5 cm, as this leads to unnecessary healthcare utilization without clinical benefit 1, 2
• Do not obtain follow-up imaging before 8 weeks, as functional cysts need adequate time to resolve through at least one menstrual cycle 1, 2
• Ensure complete visualization of larger cysts using both transvaginal and transabdominal approaches, as incomplete evaluation may miss wall abnormalities 1

When to Escalate Care

• Cyst persists or enlarges at 8-12 week follow-up 1, 2
• Development of solid components, papillary projections, or septations 1
• Abnormal Doppler flow patterns suggesting vascularity within solid areas 1
• Patient develops acute symptoms (pain, torsion, rupture) 3