Importance of Endometrial Sampling to Detect Endometrial Cancer in Post-Menopausal Patients

Due to a recent case, CPSM reminds registrants of the importance of endometrial sampling as part of a complete workup to rule out endometrial cancer as a cause of post-menopausal bleeding.

A postmenopausal patient presented reporting vaginal bleeding associated with symptoms of bloating and occasional loss of bladder control. On examination, her physician reported the cervical os to be small and no comment on the role of endometrial biopsy was documented on the patient’s chart. Instead, the patient was referred for an ultrasound.

Notably, this clinical presentation occurred during the pandemic and the ultrasound took four months to obtain. The ultrasound demonstrated a thin endometrial lining (2mm) and a cavity distorted by fibroids. At follow-up, the provider noted that blood was visible at the cervix, but because the cervical os appeared small and atrophic, an endometrial sample could not be obtained. The patient was therefore referred for endometrial sampling. Within a month, the patient was seen and an endometrial aspiration was performed in the clinic (4.5 months following the patient’s initial presentation with post-menopausal bleeding). The pathology report indicated a high-grade endometrial cancer.   

The most common initial presentation for endometrial cancer is abnormal vaginal bleeding and any postmenopausal bleeding should be promptly investigated to rule out endometrial cancer.

The Society of Obstetricians and Gynecologists of Canada recommends that histologic endometrial evaluation and transvaginal ultrasound are the preferred initial diagnostic investigations for patients with suspected endometrial cancer. However, endometrial thickening does not occur universally with endometrial cancer and, particularly with high-grade endometrial cancer, a thin endometrial lining on ultrasound can provide false reassurance. Endometrial sampling can be obtained through the following techniques:

• Endometrial biopsy (i.e. using the Pipelle device) can be performed in patients in a clinic setting as little to no cervical dilatation is needed in most cases. While briefly uncomfortable, the biopsy can usually be performed without anesthesia.
• Hysteroscopy and dilatation and curettage are available through referral to gynecologic care providers. While this procedure requires anesthesia and must be booked in a procedure room or operating room, it is especially helpful in cases where endometrial biopsy is not possible in a clinic setting. 

This case serves as a reminder about the importance of:

1. Timely care to investigate post-menopausal bleeding; and
2. awareness that ultrasound is not reliable for high-grade endometrial cancers.

As such, timely endometrial sampling (or referral for such) should be prioritized, particularly if there is a delay in accessing diagnostic imaging and when symptoms persist despite a double wall endometrial thickness of ≤ 5mm.