What is the interpretation and recommended management of an ultrasound showing endometrial thickness of 7.6 mm, a 6 × 4 mm vascularized echogenic lesion in the upper endometrial cavity suggestive of a polyp, and uterine fibroids?

Ultrasound Interpretation and Management

Primary Interpretation

This ultrasound demonstrates a focal vascularized endometrial lesion highly suspicious for an endometrial polyp in the setting of borderline-thickened endometrium, requiring mandatory tissue diagnosis via endometrial biopsy or hysteroscopy regardless of menopausal status. 1

---

Key Ultrasound Findings Analysis

Endometrial Thickness Assessment

• 7.6 mm endometrial thickness falls into an intermediate zone that requires clinical context:
  • If postmenopausal: This exceeds the 4 mm threshold (which has nearly 100% negative predictive value for malignancy) and warrants endometrial sampling 1
  • If premenopausal: This thickness may be physiologic depending on cycle phase, but the presence of a focal vascularized lesion changes management regardless 1

Focal Vascularized Lesion

• The 6 × 4 mm echogenic area with internal vascularity is the critical finding requiring action 1
• Vascularized endometrial lesions significantly increase risk of pathology, with color Doppler improving specificity for detecting abnormal conditions 2, 3
• Echogenic endometrial fluid or masses with vascularity carry an odds ratio of 10.94 for non-benign conditions (including hyperplasia and malignancy) 3

---

Mandatory Next Steps

1. Endometrial Tissue Sampling (First-Line)

Hysteroscopy with directed biopsy is the preferred approach for focal lesions rather than blind sampling techniques: 1

• Hysteroscopy allows direct visualization to distinguish between endometrial polyps, submucosal fibroids, and other pathology 1, 4
• Blind endometrial sampling (Pipelle) has 99.6% sensitivity for diffuse carcinoma but may miss focal lesions 1
• If office-based sampling is inadequate, proceed to fractional curettage under anesthesia (95% diagnostic yield) 5

2. Alternative: Sonohysterography (If Hysteroscopy Unavailable)

• Saline infusion sonography can distinguish focal from diffuse pathology with 96-100% sensitivity 5, 4
• Helps characterize whether the lesion is a polyp versus submucosal fibroid 4
• However, imaging alone cannot replace tissue diagnosis 1

---

Differential Diagnosis Priority

Most Likely (in order of probability):

1. Endometrial polyp - Most common focal vascularized endometrial lesion; typically appears as well-defined, isoechoic to endometrium with preserved endometrial-myometrial interface 4
2. Submucosal fibroid - Usually hypoechoic, broad-based with overlying endometrium; may distort endometrial-myometrial interface 4
3. Focal endometrial hyperplasia - Less common as focal finding but possible 4
4. Early endometrial carcinoma - Can present as polypoid mass in early stages; must be excluded 4, 6

---

Critical Management Pitfalls to Avoid

Do NOT:

• Assume benign polyp without tissue diagnosis - Early endometrial cancer can mimic polyps on imaging 4
• Rely on endometrial thickness alone - Abnormal echogenicity and vascularity correlate with pathology even when thickness appears reassuring 1
• Proceed with fibroid-specific treatments (UAE, ablation) without first excluding endometrial malignancy via biopsy 1
• Use blind sampling as definitive if negative - Focal lesions require direct visualization 1

Special Consideration for Postmenopausal Women:

• If postmenopausal with this finding, malignancy risk is substantially elevated 3, 6
• None of the patients with endometrial adenocarcinoma in one study had endometrial thickness ≤3 mm, but 9.4% had thickness ≤4 mm 6
• Echogenic fluid or masses are the strongest predictor of non-benign pathology (OR 10.94) 3

---

Clinical Context Considerations

If Premenopausal:

• Assess for abnormal uterine bleeding symptoms
• Even asymptomatic focal vascularized lesions warrant tissue diagnosis to exclude atypical hyperplasia or malignancy 1

If Postmenopausal:

• Any postmenopausal bleeding with this finding mandates immediate tissue sampling 1, 6
• Even if asymptomatic, endometrial thickness >4 mm with focal vascular lesion requires evaluation 1, 3

Regarding the Uterine Fibroids:

• Document fibroid locations and sizes for surgical planning if needed
• In postmenopausal women, fibroids typically shrink; any growth raises suspicion for leiomyosarcoma (though rare: 2.94 per 1,000 overall, rising to 10.1 per 1,000 in women aged 75-79) 1
• Complete pathologic evaluation via hysterectomy specimen is the only definitive way to exclude sarcoma 1