What does your ultrasound report say, they give an indication of what they think they are. No one knows what the mass is until they biopsy the tumor. Did your mother have ovarian cancer? Did they do a CA 125? are you seeing a Gyn/Onc for the surgery. The majority of ovarian masses are benign, however as I related above, you don't know until it is biopsied. Call your Dr. and ask them any questions you have on Monday. You may consider a second opinion or having a Gyn/Onc do the surgery, whether or not it is cancer. they have 3 additional years of education in women's surgery.