Cystic Ovarian Neoplasm?

I am post-menopausal (1 yr) and had an endovaginal ultrasound 2 weeks ago for abnormal bleeding.  The US showed a thickening of the uterine lining & fibroids, but also found that my right ovary was enlarged, with multiple cysts.  The report reads: "It has a multicystic appearance, which either represents multiple simple cysts abutting one another or possibly a multiseptated cystic mass...four that appear to be simple cysts, but another couple having the appearance of a cyst with a thin septation.  No mural nodularity.  The appearance is suspicious enough to warrant at least short-term interval followup, as the possibility of an ovarian neoplasm is raised."  

I had another US with my GYN yesterday which showed no change, and he wants me to have another in 30 days and says that I will probably need to have the cysts removed.  My question is, what is an ovarian neoplasm and could this suggest ovarian cancer?

Thank you in advance!