A heterogeneous endometrium finding on an imaging report often causes concern regarding cancer. The endometrium is the inner lining of the uterus, and its appearance on an ultrasound is a common part of gynecological assessment. While a heterogeneous appearance requires investigation, this descriptive term is not a diagnosis of malignancy. The vast majority of causes for an uneven-looking endometrium are benign.
Understanding Heterogeneous Endometrium
The endometrium is a dynamic tissue responding to monthly fluctuations of reproductive hormones. In premenopausal women, the lining thickens and sheds in a predictable cycle, giving it a relatively uniform, or homogenous, appearance during certain phases. A heterogeneous appearance, typically noted on a transvaginal ultrasound, means the tissue has an irregular texture and density.
This variation means the echoes returned to the ultrasound machine are not consistent throughout the lining. The image may show patchy, speckled, or focally thickened areas instead of a smooth appearance. “Heterogeneous” is a descriptive finding from an imaging study, not a medical diagnosis. This observation indicates the uterine lining structure is irregular and requires further investigation.
Common Causes of Endometrial Heterogeneity Beyond Cancer
Numerous benign conditions can alter the lining’s texture and thickness, leading to a heterogeneous appearance. The most frequent causes are non-cancerous changes that create localized irregularities. Primary among these are endometrial polyps, which are localized overgrowths of the lining. These growths are typically attached to the uterine wall by a stalk and can cause irregular bleeding, but they are benign.
Endometrial hyperplasia is another frequent cause, involving excessive thickening of the lining due to unopposed estrogen stimulation. While this condition can be precancerous, especially “atypical hyperplasia,” it is not cancer itself and is often treatable with hormonal medication. Simple hyperplasia, which occurs without atypical cells, has a low likelihood of progressing to malignancy.
Structural issues like submucosal fibroids, which are benign muscle tumors located beneath the endometrial layer, can push into the lining and cause an uneven appearance. Normal hormonal variations in premenopausal women can also result in temporary irregularity, especially if the scan is performed during the luteal phase. The presence of an intrauterine blood clot or retained tissue after a procedure can similarly present as a heterogeneous pattern.
How Doctors Investigate Endometrial Changes
Moving from an imaging finding of heterogeneity to a definitive diagnosis relies on assessment and tissue sampling. The initial step is typically a transvaginal ultrasound (TVS), which measures endometrial thickness (ET). In postmenopausal women, an ET greater than 4 to 5 millimeters is considered abnormal and warrants further testing.
Tissue sampling is the definitive way to confirm or rule out cancer or a precancerous condition, as imaging alone cannot determine cellular structure. The most common diagnostic procedures are an endometrial biopsy or a hysteroscopy. An endometrial biopsy involves inserting a thin tube through the cervix to suction a small tissue sample from the lining for pathological analysis.
Hysteroscopy is a valuable procedure where a doctor inserts a thin camera into the uterus to visually inspect the endometrial cavity. This allows for the precise location and removal of focal lesions, such as polyps or fibroids, and provides a comprehensive sample for analysis. The final treatment plan depends entirely on the results of the tissue analysis, not just the initial ultrasound report.