Typical greyscale and Doppler ultrasound features of an endometrial polyp.

There is a small amount of fluid (probably hemorrhage) present in the endometrial cavity, which helps outline the mass in this case. In the absence of fluid, endometrial polyps may be subtle as their echogenicity is similar to that of the myometrium. This is particularly the case later in the menstrual cycle, when the sensitivity of ultrasound for small polyps is reduced.

If there is a high level of suspicion for endometrial pathology in a patient being scanned during the secretory phase, consider bringing them back earlier in a subsequent cycle when the endometrium is thinner.