Borderline ovarian tumors can mimic more aggressive malignancies. (Pathology Report Critical).

LAKE TAHOE, NEV. -- Borderline ovarian tumors often present very similarly to frank ovarian cancer, but their treatment is more straightforward and survival rates are substantially better, according to one expert.

Symptoms and imaging may not give many clues to help differentiate these two kinds of tumors, Dr. Gary Leiserowitz said at an obstetrics and gynecology conference sponsored by the University of California, Davis.

In either case, ultrasound or CT scans will appear very abnormal, and the mass will often measure greater than 5-8 cm and demonstrate complex morphologic characteristics.

"It's not going to look reassuring, but it's a minority of these patients that actually have a malignancy. A high percentage of [reproductive-age women] will have something like endometriosis or a dermoid cyst, and then a certain proportion will have borderline tumors, said Dr. Leiserowitz, chief of gynecologic oncology at the University of California, Davis.

A patient with a borderline ovarian tumor may have pain, bloating, or have just a pressure sensation. There is a wide range of symptoms, and they are not remarkably different than what's associated with frank ovarian malignancies, he said.

Surgery is the primary treatment for borderline ovarian tumors, also known as ovarian tumors of low malignant potential. Although these tumors are not cancerous and survival rates are good, borderline ovarian tumors may occasionally recur, and rarely cause death.

Nearly all patients with early-stage borderline tumors survive, but there can be complications associated with advanced-stage tumors. "Deaths associated with these tumors are usually due to ascites or pseudomyxoma peritonei, or the tumor itself may cause a bowel obstruction or put pressure on a vital structure," he told this newspaper.