Introduction/Background Borderline ovarian tumors represent 10–15% of all epithelial ovarian tumors. Their prognosis is favourable, with a global survival rate of 95% in the first 5 years. Surgery is the standard management, usually bilateral salpingo-oophorectomy is carried out. Nevertheless, this neoplasm is frequent among young patients with fertility expectations. Because of this, it is common that patients are offered conservative management, consisting of unilateral or bilateral cystectomy and unilateral anexectomy.

The use of intraoperative ultrasound has been described in complex gynecological procedures. Conservative management is challenging because it must preserve the ovarian cortex while providing clear oncological margins. The objective is to present a modified technique for intraoperative ultrasound mapping in a young woman with bilateral borderline ovarian tumors in whom conservative management was successfully carried out.

Methodology 21 year old female, nulliparous with incidental finding of bilateral ovarian neoplasm and ascites in transvaginal ultrasound. CA-125 471 u/ml. Abdominal MRI does not show peritoneal compromise.

Results During surgery, a systematic revision of the abdominal cavity was performed to evaluate the extension of the disease. Intraoperative findings consisted of exophytic, papillary, bilateral ovarian tumors and white, confluent lesions present in the rectouterine pouch, vesical peritoneum and right diaphragm. While preserving oncologic hygiene, bilateral tumorectomy was done with ultrasonic energy. Afterwards, intraoperative abdominal ultrasound was performed using the transvaginal transductor over the ovarian cortex and transvaginally. It was confirmed that neither ovary had residual neoplasms. Pelvic peritonectomy was carried out.

The pathology report confirmed a borderline serous ovarian tumor stage IIIA2 with non-invasive implants. There was no indication for adjuvant therapy. Since, the patient continues in follow up with no symptoms and persistently low levels of CA-125.

Conclusion Intraoperative ultrasound mapping is a safe and easily achievable option in fertility sparing management. More evidence and bigger cohorts should be carried out to standardize its use.