Heterogeneous Endometrium (Uterine Lining) on Transvaginal Ultrasound
Heterogeneous endometrium on sonography is an ultrasound feature associated with increased likelihood of endometrial pathology, including endometrial cancer, particularly in the setting of abnormal uterine bleeding. [1] In postmenopausal patients, a heterogeneous endometrium is used as a cancer-suspicious texture pattern rather than an atrophic appearance. [1]
Cancer-Suspicious Sonographic Pattern
ISUOG describes endometrial cancer–suggestive findings that include a heterogeneous endometrium. [1] ISUOG also lists additional concurrent suspicious ultrasound features such as irregular cysts, non-visible endometrial midline, and an irregular or ill-defined endometrial–myometrial junction. [1]
Common Benign and Other Pathologic Implications
Heterogeneous endometrial texture reflects non-uniform endometrial composition on imaging, which can occur with focal intracavitary lesions such as endometrial polyps and with diffuse proliferative processes such as endometrial hyperplasia. [2] Endometrial heterogeneity also occurs with conditions that reduce the reliability of endometrial characterization, including technical or anatomic factors that impair accurate transvaginal assessment. [3]
Influence of Menopausal Status and Symptom Context
Postmenopausal bleeding is the clinical scenario in which endometrial thickness and texture are used to guide the need for tissue sampling. [3] The use of ultrasound texture features to estimate malignancy risk is embedded in the evaluation of abnormal uterine bleeding and postmenopausal bleeding rather than routine screening in asymptomatic patients. [1]
Initiation of Diagnostic Evaluation
For postmenopausal bleeding, transvaginal ultrasound is used for triage, with the clinical pathway incorporating endometrial imaging results to determine whether further evaluation is needed. [3] ISUOG indicates that when sonographic findings are concerning for malignancy, endometrial tissue evaluation is required rather than reassurance based on imaging texture alone. [1] ACR states that abnormal endometrial echogenicity and texture are among ultrasound features that prompt further evaluation with endometrial tissue sampling in both postmenopausal and premenopausal patients with abnormal uterine bleeding. [4]
Tissue Sampling Failure and Persistent Bleeding
ACOG notes that rare endometrial cancers can present with thin endometrial thickness, and that persistent or recurrent uterine bleeding should prompt histologic evaluation regardless of measured endometrial thickness. [3] Sampling failure rates for biopsy can be substantial, supporting repeat evaluation when bleeding persists after an inconclusive or insufficient initial result. [3]
Targets for Clinical Action Based on Ultrasound Interpretation
When heterogeneous endometrium is accompanied by other cancer-suspicious features, expedited diagnostic steps are indicated because endometrial cancer is within the differential. [1] When heterogeneous endometrium is identified in abnormal uterine bleeding, management should include evaluation for hyperplasia and focal lesions, with tissue diagnosis prioritized when imaging is concerning. [2][4]
Practical Differential Diagnosis Framework
Endometrial heterogeneity on ultrasound should be interpreted as a nonspecific imaging abnormality that can correspond to benign focal lesions, diffuse proliferative changes, infection or retained material, or malignancy depending on menopausal status and bleeding pattern. [2] Endometrial heterogeneity should also be interpreted in the context of ultrasound quality, because anatomic or technical factors can contribute to difficulty in reliably assessing endometrial thickness and texture. [3]
Key Distinguishing Feature Set for Higher-Risk Imaging
Higher-risk imaging patterns include heterogeneous endometrium plus irregular cysts, non-visible midline, and an irregular or ill-defined endometrial–myometrial junction. [1] When these higher-risk features are present, imaging should be treated as suggestive of endometrial cancer until histologic evaluation excludes malignancy. [1]