What Does A Hypoechoic Cystic Lesion In Ovary Indicate?

.I am a 24 yr old unmarried women having a height of 155 cm and a weight of 54 kg. I had a scan today and was reported with a well defined hypoechoic cystic lesion on right ovary .lesion is of 102 x 80 mm size with hypoechogenic shadows.myometric and endometric echoes are normal.no focal myometrial lesions are seen.i have irregular periods over the last 3 months.no distinguishable pain was noted.but i have backpain over the last 3 weeks.my doctor suggested a surgery of the cyst.is this any kind of cancerous growth?