What's your diagnosis based on this incidental finding in an elderly postmenopausal patient with a history of pain in the right hypochondrium?

The endometrium is markedly thickened, measuring more than 22 mm. There is no definite evidence on Doppler imaging of a feeder vessel supplying the lesion. In addition, the lesion is markedly echogenic, thus ruling out a submucosal fibroid.

Challenge your diagnostic skills: Can you identify this incidental finding in an elderly postmenopausal woman?