Is an ovarian septated cyst dangerous?

Ovarian Septated Cysts: Risk Assessment and Management

Ovarian septated cysts without solid areas or papillary projections have a very low risk of malignancy (less than 1%) and are generally not dangerous. 1, 2

Risk Assessment of Septated Ovarian Cysts

Classification and Risk Stratification

According to the Ovarian-Adnexal Reporting and Data System (O-RADS), septated cysts without solid components or papillary projections fall into the following categories:

• O-RADS 2 (Almost Certainly Benign, <1% risk of malignancy): Unilocular cysts with smooth walls or septations less than 10 cm 1
• O-RADS 3 (Low Risk, 1-<10% risk of malignancy): Septated cysts ≥10 cm or with irregular inner walls 1

Evidence on Malignancy Risk

A comprehensive study of 1,319 women with 2,870 septated cystic ovarian tumors without solid areas or papillary projections found:

• Only one case of borderline malignancy (Stage IB) among 128 surgically removed tumors
• Only one case of ovarian cancer developed in a contralateral ovary after 3.2 years
• After 7,642 total follow-up years, the remaining patients remained free of ovarian neoplasia 2

Management Recommendations

For Premenopausal Women:

• Simple or septated cysts <5 cm: No follow-up needed 1
• Simple or septated cysts 5-10 cm: Annual follow-up ultrasound 1
• Septated cysts >10 cm: Referral to gynecologist for evaluation 1

For Postmenopausal Women:

• Simple or septated cysts <5 cm: Follow-up ultrasound in 8-12 weeks 1
• Simple or septated cysts 5-10 cm: Referral to ultrasound specialist or MRI 1
• Septated cysts >10 cm: Referral to gynecologist 1

Potential Complications

While malignancy risk is very low, septated ovarian cysts may occasionally cause:

• Torsion: Risk of 0.2-0.4% in benign-appearing lesions 1
• Rupture: Risk of 0.2-0.4% in benign-appearing lesions 1

These complications are more likely with larger cysts (>5 cm) but remain uncommon 1, 3.

Imaging Recommendations

• First-line imaging: Transvaginal ultrasound combined with transabdominal ultrasound 1
• Color or power Doppler: Should be included to evaluate vascularity of any solid components 1
• MRI: Consider if ultrasound is inconclusive or for follow-up of lesions that cannot be adequately assessed by ultrasound 1
• CT or PET/CT: Not recommended for evaluation of likely benign adnexal masses 1

Key Points to Remember

• The vast majority of septated cysts without solid components are benign
• Many septated cysts (38.8%) resolve spontaneously within 12 months 2
• Risk of malignancy in unilocular or septated cysts without solid components is extremely low, even in postmenopausal women 4, 5, 6
• Regular ultrasound follow-up is sufficient for most septated cysts rather than immediate surgical intervention 1, 2

In summary, while any ovarian abnormality warrants proper evaluation, septated ovarian cysts without solid components or papillary projections have an excellent prognosis with minimal risk of serious complications or malignancy.