Ok what is 3mm of fat on ovary?cancer?

It depends: Fat on the ovary depends on location and how the fat is identified. If fat is seen by imaging or by the surgeon to be attached to the surface, it most likely will be an adhesion with the omentum or abdominal wall. If fat is seen inside the ovary on imaging, it may indicate a teratoma (dermoid cyst), most often a benign lesion. Pathologic evaluation is necessary to exclude a lesion in the ovary.

Not cancer: Fat can be found in and around any organ. Fat usually looks different from cancer on imaging studies and especially under a microscope.

Unlikely: Fat on the ovary is more often associated with a dermoid or benign cystic teratoma tumor. This is a benign tumor of the ovary. Crazy as it sounds, these tumors can also grow hair and teeth! you can only find out by having tumor removed and examined by a pathologist, but this is most likely what it means.