Ultrasound Follow-up for Ovarian Cyst: Normal Findings Assessment
Yes, this ultrasound demonstrates normal findings for a premenopausal woman on day 9 of her menstrual cycle, with no evidence of a persistent pathologic ovarian cyst requiring intervention. The findings show physiologic follicular development consistent with the follicular phase of the menstrual cycle, and the previously noted ovarian cyst has resolved.
Key Normal Findings Explained
Uterine Findings
- Retroverted uterus: This is a normal anatomic variant present in approximately 20% of women and requires no intervention 1
- Endometrial thickness of 4mm on day 9: This is within normal limits for the proliferative phase of the menstrual cycle 1
Right Ovary Findings
- Multiple dominant follicles (10mm, 8-9mm range): These represent normal physiologic follicular development during the follicular phase of the menstrual cycle 1
- According to O-RADS classification, follicles <3cm are considered O-RADS 1 (normal ovary, 0% likelihood of malignancy) in premenopausal women 1
- The presence of multiple follicles measuring 8-10mm on day 9 of the cycle is consistent with normal ovarian function and approaching ovulation 1
Left Ovary Findings
- Within normal limits: No abnormalities detected 1
Absence of Free Fluid
- No free fluid noted: This is reassuring as it excludes complications such as cyst rupture or hemorrhage 2, 3
Clinical Interpretation
The previously documented ovarian cyst has resolved, which is the expected outcome for functional cysts in premenopausal women. According to the American College of Radiology guidelines, hemorrhagic functional cysts typically decrease or resolve on sonographic follow-up in 8-12 weeks 2. The current ultrasound shows only normal physiologic follicles, confirming that the original cyst was functional in nature.
What Constitutes Normal vs. Pathologic Follicles
- Physiologic follicles: Unilocular, anechoic cysts <3cm are considered normal ovarian structures in premenopausal women 1
- Pathologic cysts: Would demonstrate features such as solid components, thick walls, septations, or size ≥3cm requiring further evaluation 1
Management Recommendation
No further imaging follow-up is required based on these findings 2, 4. The American College of Radiology recommends that simple cysts ≤3cm in premenopausal women should be considered physiologic and require no follow-up 4. Since all visualized follicles are <3cm and demonstrate normal characteristics, this represents successful resolution of the original cyst with return to normal ovarian function 1, 2.
Important Considerations
Distinguishing Normal Follicles from PCOS
While multiple follicles are present, this does not indicate polycystic ovary syndrome (PCOS) because:
- PCOS requires ≥12 follicles measuring 2-9mm in diameter per ovary, or increased ovarian volume >10cm³ 5
- The report describes only 2 dominant follicles on the right ovary, which is normal for mid-follicular phase 6, 5
- PCOS diagnosis requires additional clinical criteria beyond ultrasound findings (hyperandrogenism, ovulatory dysfunction) 1
Common Pitfall to Avoid
Do not confuse normal physiologic follicular development with pathologic cysts or PCOS 1, 2. The timing of the ultrasound (day 9 of cycle) is ideal for assessing ovarian morphology during the proliferative phase when functional cysts should have resolved 2, 4.