Management of Adnexal Cysts

Initial Evaluation

• The American College of Radiology recommends transvaginal ultrasound combined with transabdominal ultrasound as the most useful initial approach for evaluating suspected adnexal masses 1
• The American College of Radiology suggests including color or power Doppler in the ultrasound examination to evaluate vascularity of any solid component 1
• Adnexal masses can be categorized as cystic, solid, or mixed based on sonographic appearance, according to the American College of Radiology 2

Management Based on Cyst Type

Simple Cysts

• Simple cysts establish a benign process in 98.7% of premenopausal women, as reported by the American College of Radiology 2
• The American College of Radiology recommends follow-up only for simple cysts >3 cm (or >5 cm if exceptionally well visualized) in postmenopausal women 1
• For premenopausal women, simple cysts ≤3 cm require no follow-up, according to Radiology 3

Hemorrhagic Cysts

• Premenopausal hemorrhagic cysts ≤5 cm require no further management, as stated by Radiology 4
• Premenopausal hemorrhagic cysts >5 cm but <10 cm require follow-up in 8-12 weeks, according to Radiology 4
• Hemorrhagic cysts in postmenopausal women warrant further evaluation by ultrasound specialist, gynecologist referral, or MRI, as recommended by Radiology 4

Dermoid Cysts and Endometriomas

• For premenopausal patients with dermoid cysts or endometriomas <10 cm, optional initial follow-up at 8-12 weeks with annual surveillance if not surgically removed is suggested by Radiology 4
• In postmenopausal patients, annual ultrasound follow-up may be considered, but the risk of malignant transformation is higher for endometriomas, according to Radiology 4
• If morphology changes or vascular components develop, referral to ultrasound specialist or MRI is recommended by Radiology 3

Risk Stratification and Referral

O-RADS Classification System

• O-RADS 3 lesions (1% to <10% risk of malignancy) should be managed by a general gynecologist with possible ultrasound specialist consultation or MRI, as recommended by Radiology 3
• O-RADS 4 lesions (10% to <50% risk of malignancy) require consultation with gynecologic oncology prior to removal or referral for management, according to Radiology 3
• O-RADS 5 lesions (50%-100% risk of malignancy) warrant direct referral to a gynecologic oncologist, as stated by Radiology 3

Indeterminate Masses

• Up to 22-24% of adnexal masses remain indeterminate after initial ultrasound, according to the American College of Radiology 1
• MRI is the most useful modality for further evaluation of indeterminate lesions, as recommended by the American College of Radiology 1
• CT is not recommended for characterization of indeterminate adnexal masses, according to the American College of Radiology 1

Special Considerations

• Initial management by a gynecologic oncologist is the second most important prognostic factor (after stage) for long-term survival in patients with ovarian malignancy, as reported by the American College of Radiology 2
• Surgical exploration of benign lesions has reported complication rates of 2-15%, emphasizing the importance of accurate preoperative characterization, according to the American College of Radiology 2

Pitfalls to Avoid

• Misinterpreting endosalpingeal folds in hydrosalpinx as solid components should be avoided, as warned by Radiology 4
• Mistaking pedunculated leiomyomas for solid ovarian masses can be avoided by careful identification of normal ovaries and blood supply from uterine vessels, according to the American College of Radiology 2
• Relying on CT for characterization of adnexal masses when MRI is better established for this purpose should be avoided, as stated by the American College of Radiology 1
• Assuming all cysts in postmenopausal women are malignant is incorrect, as recent evidence shows simple cysts have very low malignancy risk regardless of menopausal status, according to the American College of Radiology 1

Imaging and Management Guidelines for Post‑Hysterectomy Adnexal Cysts

Initial Imaging Evaluation

• Transvaginal ultrasound with color‑ or power‑Doppler is the first‑line study to assess vascularity of solid components and to determine the origin of an adnexal mass (American College of Radiology) 5
• Transabdominal ultrasound should be added to guarantee complete visualization, especially when the cyst is large (American College of Radiology) 5
• Ultrasound must classify the cyst as simple, complex, or possessing concerning malignant features (American College of Radiology) 6

Risk Stratification Based on Ultrasound Findings

• In post‑menopausal women with ovarian preservation after hysterectomy, 53 % of simple cysts resolve completely and 28 % remain stable on follow‑up imaging (American College of Radiology) 5
• Features that raise suspicion for malignancy include thick or irregular septations, mural nodules, solid or papillary components, and a diameter greater than 5 cm (American College of Obstetricians and Gynecologists) 7

Advanced Imaging for Indeterminate Lesions

• When ultrasound cannot adequately characterize a mass, pelvic MRI with intravenous contrast is the recommended next imaging modality (American College of Radiology) 5
• CT is not indicated for adnexal mass characterization because of its inferior soft‑tissue discrimination (American College of Radiology) 5

Management Pathways by O‑RADS Category

• O‑RADS 5 lesions (≥50 % risk of malignancy) require direct referral to a gynecologic oncologist; specialist management is the second most important prognostic factor after tumor stage (American College of Radiology) 8

Special Considerations After Hysterectomy

• The ovaries remain functional after hysterectomy with ovarian preservation, allowing functional cysts to develop (American College of Radiology) 5
• Endometriomas that are not surgically removed should be surveilled annually because they carry a small (<1 %) risk of malignant transformation (American College of Radiology) 5
• Dermoid (teratoma) cysts identified by echogenic components may be followed annually if they are smaller than 10 cm (American College of Radiology) 8

Critical Pitfalls to Avoid

• Do not use CT for characterization of adnexal masses; MRI provides superior soft‑tissue detail (American College of Radiology) 5
• Both transvaginal and transabdominal ultrasound approaches must be employed to ensure complete visualization and to avoid missing wall irregularities in larger cysts (American College of Radiology) 5
• Surgical exploration of lesions that are ultimately benign carries a complication rate of 2–15 %, underscoring the need for accurate pre‑operative imaging (American College of Radiology) 8