Serous borderline ovarian tumor, Staging

Dear Dr Goodman,
I am writing you from Switzerland where I am currently leaving.
My sister came to visit me in Geneva and got operated (beginning of September). During operation a cyst of about 12 cm was removed. She was not aware of having this cyst due to not going to the doctor for a few years.
Histology came back as Borderline Serous Ovarian Tumor. Description of the report
Macroscopic
Membrane with one of the surfices is smooth and beige-greyish colour. The oher side presents a few pappilary structures of Dear Dr Goodman,
I am writing you from Switzerland where I am currently leaving.
My sister came to visit me in Geneva and got operated (beginning of September). During operation a cyst of about 12 cm was removed. She was not aware of having this cyst due to not going to the doctor for a few years.
Histology came back as Borderline Serous Ovarian Tumor. Description of the report
Macroscopic description
Membrane with one of the surfices is smooth and beige-greyish colour. The oher side presents a few pappilary structures.
Microscopic description
Cyst wall represents unicellular serous epithelium presenting atypical cytonuclears with increased report of nuclear to cytoplasm and moderate nuclear pleomorphisme with prominent nuclei. Presence of pseudostratification with presence of pseudo papillae as well as presence of microcalcification is noticed. Absence of invasion.
Diagnosis - Cystectomy of left ovary. Borderline serous ovarian tumor.
As that was an emergency operation during the night, no diagnosis was made based on frozen section neither staging. What would be you suggestion as a further action - affected ovary removal and staging?
Thanks a lot for your advice.
Kind regards, Ilyana

[Annekathryn Goodman, M.D.]

Dear Ilyana

Your sister is lucky and she should be fine!  
here is a link

http://emedicine.medscape.com/article/258970-overview

I would recommend follow up CA 125 testing and yearly pelvic ultrasounds to keep an eye on the other ovary. Once she is in menopause, she should have a prophylactic removal of the other ovary and fallopian tube.
best wishes