What is the recommended workup for a patient presenting with an ovarian cyst?

Workup for Ovarian Cyst

Begin with transvaginal ultrasound combined with transabdominal imaging and color/power Doppler to characterize the cyst, then stratify management based on the O-RADS classification system, menopausal status, and cyst size. 1, 2

Initial Imaging Evaluation

• Perform transvaginal ultrasound as the primary diagnostic modality, augmented with transabdominal approach for complete evaluation 1, 2, 3
• Include color or power Doppler assessment to evaluate vascularity of any solid components 1, 2
• Document the following key features:
  • Maximum cyst diameter (measured in largest plane) 1, 2
  • Cyst characteristics: unilocular vs. multilocular, wall thickness, presence of septations 1, 2
  • Solid components or papillary projections (count if present) 2
  • Presence of ascites 2

Risk Stratification Using O-RADS Classification

Apply the Ovarian-Adnexal Reporting and Data System to determine malignancy risk 1, 2, 3:

• O-RADS 1: Physiologic (normal ovarian findings) 2, 3
• O-RADS 2: Almost certainly benign (<1% malignancy risk) - simple or multilocular smooth-walled cysts <10 cm 1, 2
• O-RADS 3: Low risk (1-10% malignancy) - multilocular cysts ≥10 cm or any size with increased vascularity 2, 3
• O-RADS 4: Intermediate risk (10-50% malignancy) 2, 3
• O-RADS 5: High risk (50-100% malignancy) 2, 3

Laboratory Testing

• Measure serum CA-125 before any surgical intervention or if malignancy is suspected 3
• Consider additional tumor markers (CEA, CA19.9) only if CA-125 is not elevated 3
• Do not routinely obtain tumor markers for simple cysts with benign features 1, 3

Management Algorithm Based on Menopausal Status and Cyst Characteristics

Premenopausal Women

Simple cysts:

• ≤5 cm: No follow-up required 1, 3
• 5-10 cm: Follow-up ultrasound in 8-12 weeks during proliferative phase (after menstruation) to allow functional cysts to resolve 1, 2, 3
• ≥10 cm: Surgical management 3

Hemorrhagic cysts:

• ≤5 cm: No further management needed (typically resolve in 8-12 weeks) 1, 3

• 5 cm: Follow-up ultrasound in 8-12 weeks 1, 3

Endometriomas and dermoid cysts:

• Optional initial follow-up at 8-12 weeks, then yearly ultrasound surveillance due to small malignant transformation risk 1, 3

Postmenopausal Women

Simple cysts:

• ≤3 cm: No further management 1, 3

• 3 cm but <10 cm: Follow-up ultrasound at 1 year showing stability or decrease in size; consider annual surveillance for up to 5 years if stable 1, 2, 3

• ≥10 cm: Surgical management 3

Hemorrhagic cysts:

• Require further evaluation by ultrasound specialist, gynecologist referral, or MRI (unlike premenopausal women where these are typically benign) 3

Endometriomas and dermoid cysts:

• Consider annual ultrasound follow-up 3

Referral Guidelines Based on O-RADS Category

• O-RADS 2: Manage conservatively with surveillance as outlined above 1, 2
• O-RADS 3: Refer to general gynecologist; consider ultrasound specialist evaluation or contrast-enhanced MRI for further characterization 2, 3
• O-RADS 4: Require gynecologic oncology consultation prior to surgical removal 2, 3
• O-RADS 5: Direct referral to gynecologic oncologist (initial surgery by gynecologic oncologist improves outcomes through complete staging) 2, 3

Advanced Imaging for Indeterminate Masses

• Use contrast-enhanced MRI for further characterization of indeterminate adnexal masses, as it performs superiorly to both ultrasound and noncontrast MRI 2, 3
• Noncontrast MRI can achieve 85% sensitivity and 96% specificity when IV contrast is contraindicated 3
• CT is not useful for characterization of indeterminate adnexal masses 2, 3
• PET/CT cannot reliably differentiate benign from malignant adnexal lesions 2, 3

Critical Pitfalls to Avoid

• Do not perform fine-needle aspiration or transvaginal aspiration of ovarian masses - this is contraindicated for solid/mixed masses and for purely fluid cysts >5 cm in postmenopausal women 3
• Do not operate prematurely on simple cysts <10 cm - the risk of malignancy in unilocular cysts is only 0.5-0.6% in premenopausal women and <1% overall 1, 3
• Do not fail to perform adequate follow-up for cysts >5 cm, as larger cysts may be more challenging to evaluate completely 1, 2
• Do not overlook functional cysts in premenopausal women - these typically resolve within 8-12 weeks, making timing of follow-up during the proliferative phase essential 1, 2
• Do not assume all persistent cysts are pathological - many benign neoplasms can be safely followed, with acute complications (torsion, rupture) occurring in only 0.2-0.4% 1, 3

Key Clinical Context

The risk of malignancy in simple cysts <10 cm is extremely low (<1%), with no malignancies found among 12,957 simple cysts in women under 50 years 1, 3. In postmenopausal women, only one malignancy was found among 2,349 simple cysts at 3-year follow-up 3. This robust evidence supports conservative management with appropriate surveillance rather than immediate surgical intervention for benign-appearing lesions.