My aunt has hyperechoic mass in endometrial canal, what does that mean? i'm very scared for her.

Not enough info: I know you're worried about your aunt but this mass is likely to be benign and not cancer. Commonly a mass in the uterine cavity is benign most commonly a fibroid or a polyp. The most important thing is that she is being seen by a competent and caring Gynecologist.

Dense mass.: Hyperechoic refers to the density of the mass; it implies that the tissue is more dense than normal tissue. The majority of uniformly hyperechoic endometrial polyps are benign. It merits a visit to ones gynecologist or to a gynecologic oncologist.