What does an ultrasound report showing no adnexal mass, normal‑size ovaries (right 40 × 28 mm, left 37 × 21 mm) and a 24 × 25 mm thin, smooth‑walled cyst with internal echoes in the right ovary (suggestive of a hemorrhagic cyst) mean?

Understanding Your Ultrasound Report: Hemorrhagic Ovarian Cyst

Your ultrasound shows a benign hemorrhagic (blood-filled) cyst in your right ovary measuring approximately 24-25 mm, which falls into the O-RADS 2 category with less than 1% risk of malignancy and typically requires no immediate intervention if you are premenopausal. 1

What Each Finding Means

Normal Ovarian Size

• Right ovary: 40 × 28 mm and Left ovary: 37 × 21 mm are within normal size ranges for reproductive-aged women 1
• Normal ovarian dimensions typically range from 25-50 mm in length, so your measurements are reassuring 1

"No Adnexal Mass"

• This confirms there are no suspicious masses or tumors in the areas around your ovaries (the adnexa includes ovaries, fallopian tubes, and surrounding structures) 1
• This is an important negative finding that helps rule out concerning pathology 1

The 24 × 25 mm Cyst with "Internal Echoes"

What it is:

• A hemorrhagic cyst is a functional ovarian cyst that has bled into itself, creating internal echoes (blood products) visible on ultrasound 1, 2
• The "thin and smooth walled" description is a benign feature that indicates this is almost certainly not cancerous 1

Why it happens:

• Hemorrhagic cysts commonly develop during normal ovarian function when a corpus luteum or follicle bleeds internally 2, 3
• These are extremely common in premenopausal women and represent normal physiologic variations 1

Risk Stratification

According to the ACR O-RADS classification system:

• Your cyst qualifies as O-RADS 2 (Almost Certainly Benign) with less than 1% malignancy risk 1
• Classic hemorrhagic cysts under 10 cm have essentially 0% malignancy rate in the data from over 5,900 analyzed lesions 1
• The thin, smooth wall without solid components or papillary projections is the key reassuring feature 1

Recommended Management

If You Are Premenopausal:

• No follow-up imaging is required for hemorrhagic cysts less than 5 cm (yours is 2.4-2.5 cm) 1, 4
• These cysts typically resolve spontaneously within 8-12 weeks as the blood is reabsorbed 4, 5
• You can expect the cyst to decrease in size or disappear completely on its own 4

If You Are Postmenopausal:

• Follow-up ultrasound in 8-12 weeks is recommended to confirm resolution or stability 1
• Even in postmenopausal women, hemorrhagic cysts under 10 cm with classic benign features have less than 1% malignancy risk 1

Important Caveats

When to seek immediate care:

• Sudden severe pelvic pain could indicate cyst rupture or ovarian torsion (twisting), though this is uncommon with cysts this size 6
• Persistent or worsening pain despite conservative management warrants gynecologic evaluation 6

What makes this diagnosis reliable:

• The combination of thin walls, smooth margins, and internal echoes creates a characteristic pattern that experienced sonographers recognize with high accuracy 2, 5
• The absence of solid components, papillary projections, or irregular walls effectively rules out malignancy 1

Potential for misdiagnosis:

• Larger cysts (>5 cm) have slightly higher risk of mischaracterization on ultrasound, which is why follow-up is recommended for those 1, 4
• Your cyst at 2.4-2.5 cm is well below this threshold and can be visualized with excellent detail 1

Bottom Line

This finding represents a common, benign functional ovarian cyst that will almost certainly resolve on its own without intervention. The specific ultrasound characteristics described—thin walls, smooth margins, and internal echoes from blood—create a classic pattern for hemorrhagic cysts that experienced radiologists can diagnose with confidence. 1, 2 If you are premenopausal and asymptomatic, no further imaging or treatment is necessary. 1, 4